I've been working on little mod on my own for myself for some time now because I wasn't happy with the stuff that basic Civ4+Warlords gave. I wanted more complex game - something that is similar to DYP and RAR mods in Civ3 which I enjoyed a lot. So keeping those mods as my guideline and aiming for realism and true to the history I came up with this:

Sum up so far:
90 new techs
49 new buildings
19 new wonders
32 new unit classes
+ Ethinacally diverse units (121)
I started with researching history and re-making tech tree (it's not 100% done yet) and when I got it mostly done I started adding buildings, units etc. I included Greenmod, sevopedia, ethnically diverse units, parts from religion and civic mods and some units from Modern Warfare, Sevomod and Total Realism to give some flavor to different civilizations.. but I think I've reached the point how far I can go myself. I don't have skills for python or C++ so anything that will need changes to those is beyond my reach. I do want to add some things so it would be great if someone explains if those are possible and if are, how difficult it would be. I'd like to hear also advices how to improve the tech tree.. I'm not happy with governments and art related techs - also near future techs need some more thinking. I'd appreciate all kinds of advices what to add.
Buildings and units that I've added
So to the questions:
1. I want to add more religions (protestantism and zoroastrianism added so far) based on real world but I didn't see anywhere in XML files the options to make religions affect resources. For example how Jewish people can be made not to use pig as food resource and hindu people use cow as their holy animal?
2. If I make resource trees (oil->synthetic fibers,cotton->textiles->clothes+synthetic fibers->kevlar armor) does AI know how to build those resource lines and use them to build better units?
3. How can I make helicopters fly over coast?
4. How do I add more Civic sections (health care and cultural values) on civic screen? I've taken long time ago some cultural leadership courses and from those learnt some differencies between cultures and would like to add those values to different civilizations to make more conflicts and give more flavor to them.
5. What changes do you think I should make to that tech tree?
6. What near future techs you think we will discover during this century? What units/buildings could be associated with the techs?
7. Would it be possible to make some building produce one type units after N turns? Like palace could produce palace guards...
8. What were the religions called that Rome had before Christianity? I know they worshipped Jupiter etc. but don't know name for that religion. What did Mayas, Incas worship?
9. What government techs should be added? What effects each government should have?
10. What art techs should there be?
11. I'd like to add things like Hellenism (to work as art style/culture in a way as religions work). How that could be done? These would be part of Cultural values section in Civic options.
At the moment I don't have internet connection so I can rarely read posts here so don't mind if I don't answer for days (got limited amount of time to write my posts so got to keep it short). Also at the moment I have no intention to release this mod, since like I said at the start, I've combined so much stuff (graphics) from different mods that it would take long time to find out who had originally done each piece and then go ask their permission to use their stuff in my mod... if I have some day time to dig through resources and ask permissions, then I might re-think about releasing this to public.
I'll come back later with more questions..

Sum up so far:
90 new techs
49 new buildings
19 new wonders
32 new unit classes
+ Ethinacally diverse units (121)
I started with researching history and re-making tech tree (it's not 100% done yet) and when I got it mostly done I started adding buildings, units etc. I included Greenmod, sevopedia, ethnically diverse units, parts from religion and civic mods and some units from Modern Warfare, Sevomod and Total Realism to give some flavor to different civilizations.. but I think I've reached the point how far I can go myself. I don't have skills for python or C++ so anything that will need changes to those is beyond my reach. I do want to add some things so it would be great if someone explains if those are possible and if are, how difficult it would be. I'd like to hear also advices how to improve the tech tree.. I'm not happy with governments and art related techs - also near future techs need some more thinking. I'd appreciate all kinds of advices what to add.
Buildings and units that I've added
Spoiler :
Archery Range, +3 xp archery units
Accelerator
Amusement Park
Arena
Armourer
Artist Guild
Bath House
Bazaar, +15 commerce in city
Brothel
Casino
Commercial Airport
Commercial Port
Deep Space Research Institute
Doctor's Office
Food Processing Plant
Garrison
Glasssmith
Guild Hall
Healer's Hut
Hotel
International Port
Manufacturing Plant
Meeting Hall
Military Airbase
Movie Theatre
Museum
Naval Academy
Oil Refinery
Opera House
Orbital Factory
Orbital Hotel
Park
Police Station
Port, +25% commerce in city
Press Agency
Protestant Cathedral
Protestant Church
Sacrificial Altar
School
School of Scribes
Sewer System
Space Laboratory
Townclock
Vacation Resort
Water Treatment Plant
Weapon factory
Zoroastrian Cathedral
Zoroastrian Fire Temple
Zoroastrian Monastery
New Wonders
-------------------------
Central Bank (national)
Cure For Cancer
Einstein's Laboratory
Human Genome Project
Labor Union (national)
Leonardo's Workshop
Medical Research Institute (national)
Modern Art theatre
National Courier System (national)
Newton's University
Olympic Games
Radio Telescope
Royal tournament
Silicon Valley
Silk Road
Statue of Champion (national)
Supercollider
The Sphinx
Theory of Evolution
New Units
--------------------------
War Galley (Naval Warfare)
Trade Caravan (Trade)
Entertainer (heraldry)
Freight (combustion)
Elephant Rider (Elephant riding)
Chivalry (Chivalry)
Crusader (Fundamentalism)
Bazooka (rocketry)
ACV (nanobotics)
ACV SAM (nanobotics)
Ancient Cannon (construction, unique for china)
Cataphract (horse breeding)
Early Tank (armored Vehicles)
Strike Fighter (supersonic flight)
Guerrilla (guerrilla warfare)
Hoover Tank (skyroads)
Humvee (globalization)
KA50 Gunship (modern warfare)
AH64 Gunship (modern warfare)
Man'o'war
Ship of the line
Privateer
Mobile howitzer
Mobile SAM
Nuclear Carrier
Nuclear Submarine
Police Squad
SAM infantry
Siege Tower
Stealth Fighter
Transport Helicopter
Wardogs
+ Ethinacally diverse units (121)
New Projects
--------------
Hubble Space Telescope
International Space Station
Accelerator
Amusement Park
Arena
Armourer
Artist Guild
Bath House
Bazaar, +15 commerce in city
Brothel
Casino
Commercial Airport
Commercial Port
Deep Space Research Institute
Doctor's Office
Food Processing Plant
Garrison
Glasssmith
Guild Hall
Healer's Hut
Hotel
International Port
Manufacturing Plant
Meeting Hall
Military Airbase
Movie Theatre
Museum
Naval Academy
Oil Refinery
Opera House
Orbital Factory
Orbital Hotel
Park
Police Station
Port, +25% commerce in city
Press Agency
Protestant Cathedral
Protestant Church
Sacrificial Altar
School
School of Scribes
Sewer System
Space Laboratory
Townclock
Vacation Resort
Water Treatment Plant
Weapon factory
Zoroastrian Cathedral
Zoroastrian Fire Temple
Zoroastrian Monastery
New Wonders
-------------------------
Central Bank (national)
Cure For Cancer
Einstein's Laboratory
Human Genome Project
Labor Union (national)
Leonardo's Workshop
Medical Research Institute (national)
Modern Art theatre
National Courier System (national)
Newton's University
Olympic Games
Radio Telescope
Royal tournament
Silicon Valley
Silk Road
Statue of Champion (national)
Supercollider
The Sphinx
Theory of Evolution
New Units
--------------------------
War Galley (Naval Warfare)
Trade Caravan (Trade)
Entertainer (heraldry)
Freight (combustion)
Elephant Rider (Elephant riding)
Chivalry (Chivalry)
Crusader (Fundamentalism)
Bazooka (rocketry)
ACV (nanobotics)
ACV SAM (nanobotics)
Ancient Cannon (construction, unique for china)
Cataphract (horse breeding)
Early Tank (armored Vehicles)
Strike Fighter (supersonic flight)
Guerrilla (guerrilla warfare)
Hoover Tank (skyroads)
Humvee (globalization)
KA50 Gunship (modern warfare)
AH64 Gunship (modern warfare)
Man'o'war
Ship of the line
Privateer
Mobile howitzer
Mobile SAM
Nuclear Carrier
Nuclear Submarine
Police Squad
SAM infantry
Siege Tower
Stealth Fighter
Transport Helicopter
Wardogs
+ Ethinacally diverse units (121)
New Projects
--------------
Hubble Space Telescope
International Space Station
So to the questions:
1. I want to add more religions (protestantism and zoroastrianism added so far) based on real world but I didn't see anywhere in XML files the options to make religions affect resources. For example how Jewish people can be made not to use pig as food resource and hindu people use cow as their holy animal?
2. If I make resource trees (oil->synthetic fibers,cotton->textiles->clothes+synthetic fibers->kevlar armor) does AI know how to build those resource lines and use them to build better units?
3. How can I make helicopters fly over coast?
4. How do I add more Civic sections (health care and cultural values) on civic screen? I've taken long time ago some cultural leadership courses and from those learnt some differencies between cultures and would like to add those values to different civilizations to make more conflicts and give more flavor to them.
5. What changes do you think I should make to that tech tree?
6. What near future techs you think we will discover during this century? What units/buildings could be associated with the techs?
7. Would it be possible to make some building produce one type units after N turns? Like palace could produce palace guards...
8. What were the religions called that Rome had before Christianity? I know they worshipped Jupiter etc. but don't know name for that religion. What did Mayas, Incas worship?
9. What government techs should be added? What effects each government should have?
10. What art techs should there be?
11. I'd like to add things like Hellenism (to work as art style/culture in a way as religions work). How that could be done? These would be part of Cultural values section in Civic options.
At the moment I don't have internet connection so I can rarely read posts here so don't mind if I don't answer for days (got limited amount of time to write my posts so got to keep it short). Also at the moment I have no intention to release this mod, since like I said at the start, I've combined so much stuff (graphics) from different mods that it would take long time to find out who had originally done each piece and then go ask their permission to use their stuff in my mod... if I have some day time to dig through resources and ask permissions, then I might re-think about releasing this to public.
I'll come back later with more questions..