I have a holiday period and I want to win this scenario with all 17 civs on noble difficulty. I've been going through the more easy civs to begin. I will post more in coming days.
Difficulty:noble
Byzantines
Strongest Civ in scenario. Starts high in tech and with lots of Cataphracts which are unique unit of knight and have 12 strength. Send all of your cataphracts down to jerusalem, take it, then send 2 to Cairo, 2 to Mecca, 1 to Suhar, 2 or 3 to baghdad. After this send them all east and take Persian cities. You should be able to accomplish this with out building any units within 5-6 turns. Meanwhile build christian temple and monastery in all cities (for free hammers) and oracle in Constantinople. If you did what I said you will have won the game already. You'll get huge amounts of income from your shrines. The christian powers will not declare war on you for a couple of hundred years. China is the only real threat but won't attack for a while. You can also take India quite easily aswell after Persia though you'll need to build some trebuchet and some more Cataphracts.
France
Very easy. You have marble and stone, industrious trait and a kickass capital city and you play your turn before HRE so you can take Danzig. Run bureacracy and get a few wonders in paris: oracle, great library, taj mahal, national epic. You should be able to stay near top in tech for most of game. Go for steel when you can and use cannons to invade HRE and Spain. Don't bother going after anyone else. You should be almost always ahead in tech throughout. In the end I got a cultural victory with Paris, Danzig and Rome. Be careful of Peter in this game, he gets strong around industrial period and will go after you. But you should always be ahead of him in tech and you will be defending so you should be able to hold him off without even using significant resources.
Russia
Easy. Get oracle early by chopping forest around Novgorod. Don't settle Moscow, settle top of Sweden for copper and iron and deer and blocking in Vikings. Get exotic resources from India and China so your cities can grow larger. Send a horse archer to meet eastern civs ASAP. There are 3 barbardian cities at the beginning to the east of Kherson. Send Horse Archer to sack the one really close to Kherson, take the other 2 before 10 turns are done. If you wait too long Byzantine or Saladin will take 1, Mongols will take the other. Don't open borders with anyone apart from Elizabeth. Focus on blocking Western powers from Russian virgin land. Once you have done this you can settle it at your leisure. Watch out for occasional barbarian. Chop forests to get granaries, forges, christian temple and christian monastery (for hammers) in new cities. Settle a bit faster around the time you get Cossacks. Saladin and Genghis will also settle faster at this time. Around this time you should have a large number of cities with nearly all useful buildings built, making a lot of research and with a lot of hammers. I just spammed Cossacks at this point and invaded Saladin and then invaded India. You can do whatever you want now, no other civilization will be able to hurt you. I invaded China and then Europe with tanks. Won a diplomatic victory after Spain, France, HRE, Byzantine, China, Khymer all my vassals.
China
Quite easy. At the beginning move all your crossbowman to the northernmost city and make peace with Mongols ASAP, then develop chinese lands, get oracle and then liberalism for 2 free techs, send an archers along silk route to meet all western civs. Trade techs to become near top in score. After you have developed china begin sending settlers and mounted units up to Siberia and do it quickly, byzantine, Saladin, Russia, Mongols will all be doing the same. Try to reach ice at top so your land is all connected and its stops anyone else moving east without open borders with you. Once you get cavalry invade Mongol cities, should be easy as they only have longbowmen. With a good chunk of russia and china you'll be in the score lead at this point. If you just develop what you have noone should be able to catch you, but again beware of Peter, he is the only one who will be able to beat you at this point. Build a military to defend against him.
Arabia
Also very easy. Take all camel archers over to jerusalem, leave 1 in baghdad for barbs you should have about 8 or 9. It's very difficult to keep Corduba and Syracuse, even if you upgrade to Longbowmen they will most likely be culture flipped so forget about those places. Make peace with France, England, HRE, Byzantines though not Spain, give them a cheap tech if you have to. Then send all of your camel archers east and take India. With India, Persia, Arabia, Egypt you should be able to comfortably stay in the tech lead at all times (with shrines) you can go for whatever victory that you want. Though watch Peter from time he gets Cossacks he has good land to expand into and he is clever and he hates you Muslim heathens !
Mongols
This game was very hard for me at the beginning. I followed the guide set in the first post of this thread however I believe it doesn't work. If you send all of your army west and attack Saladin he will fairly quickly upgrade archers to Longbowmen but more quickly he will bring Camel archers which are more than a match for your horse archers, you can just about get baghdad and eastern cities (I lost my whole army taking these places, and I moved very quickly) but you definitely cannot take jerusalem without being very lucky and probably reloading the game many times.
If you look at the units Saladin has and the units China and Korea have, Saladin is further away and better defended than China and Korea, its not worthwhile.
I took the northernmost city in China as my capital and then took Korea with my 11 HA and then settled 2 cities just north, mean while my 1 archer went along the silk route through Arabian empire to meet India and all Christian civs and Mali. I converted to buddhism, gave 1 or 2 techs to Khymer and Japanese and gave Iron to Khymer then get them to declare war on China (by giving them another tech). With all 3 of you attacking from sea and north and south the Chinese don't develop at all. Use HA you have left pillage chinese countryside, China has no Iron and no horses though eventually it will make loads of musketmen and destroy your army. Try to steal workers from china during this time. Then develop your lands and try to get to Military tradition for cuirassers either by trading techs or by research. Invade china (which will be just trying to get its economy together after all war and raiding) with purely promoted cuirassers (you can storm it in 5 turns) and then you will be in lead and I stormed India then with cavalry. Then Khmer offered to become my vassal. With China and India land and Khymer vassalised you should be able to peacefully take lead in tech. And with tech advantage and loads of resources and productive cities and income from shrines and virgin Russian land to north unsettled, the world is your oyster.
One thing to note is that once I got military tradition I traded it with 5 or 6 civs for 5 or 6 different techs. Mali and Byzantines even gave me techs that are worth more than military tradition. This allowed me to go to near the top of tech lead.
Inca
Quite hard. Don't settle immediately on that hill, head west and settle so you get the 2 corn resources. Then build workboat and a scout (for the 5 tribal villages in south america) and research sailing, improve land around capital, send workboat to make contact with Aztecs. After sailing go for feudalism for serfdom and longbowmen. As soon as you get a galley ferry your troops to Argentina and settle your 2nd city around Buenos aires so you have 2 corn's and 1 fish and 2 hills, using this city you can make workers and settlers very quickly once it is grown a bit. Watch out for barbarians you don't have iron, you'll have to build longbowmen. Using your 2nd city move as quickly as possible to settle all of east coast of South America, especially important is oil and aluminium resource in Brazil. However france and HRE still managed to make a few cities up near venezuala in my game. As soon as possible convert to christianity for diplo bonus and also for extra hammers from christian temple and monastery. I then continued settling inner South America, bottom, west. At no point will you be anywhere near the top of score. Don't annoy Isabella (she always goes looking for trouble), don't worry about Elizabeth (a pacifist who doesn't usually interfere). Try to appease Louis and Charlemagne and Justinian them but not too much that they will get something worthwhile, like a tech you just researched. You can declare war on Saladin, to appease the Christians. Try to stay at peace and get computers to build Internet. Then go for a space victory. You'll have aluminium and industrious trait to make Space elevator and make laboratories ASAP. The whole game you will never be ahead in tech or military or score, diplomacy is very important.
One final note is the starting game is critical for Inca, make sure you are alway building something or researching or doing something for your overall strategy. Pick the techs you research carefully, make all your moves carefully.