Stuff I've noticed:
I'm running Civ4 Gold on a Core 2 Duo T5300 with 2GB of RAM and an Intel GMA 950... so some bugs may be due to the fact that my graphics card is below minimum specs. But hear me out first.
(Possible) Bugs-I'm sure some of them have been mentioned, but hey:
Turns seem to be erratic in how long they take to finish. I think this is probably a function of how many units there are-I carpet nuked a civilization and turn times shortened again for a bit.
Combat resolution may be borked-I lost an attack drone to an Outlaw. Yes, it was in a city defending, but that was a level 2 Attack Drone, full health, with Combat I, fighting a level 2 Outlaw (City Garrison I and II) in a city with a 20% defense bonus. Getting damaged, I could expect, but dying? Whaaat? And no, this wasn't a one-time thing. I blasted the outlaw with a hover armor... only to lose it to a spearman.
On that note, it seems that Zepplins and Biplanes are too powerful. They were doing as much damage as my stealth fighters, drones, and stealth bombers. This may be related to the strange combat resolution that I've found.
A couple of description texts have very strange numbers.
Plains are showing the event "Lost in the Doldrums" with a percentage chance of "1000000-1" or something similar.
The Attack Drone says it has +1% city attack-I have no idea why.
Tomahawk Cruise Missiles don't seem to do anything.
The Stealth Fighter is ~20% cheaper than the Stealth Bomber but better in almost every way.
The combat odds do not show up for Attack Drones, Cyborgs, and Hover Armor.
The Orbital Bomber units can only be built in the city you have the Apollo Project in. No other cities can build this unit.
Underwater bases cannot build naval units, which really sucks.
Partisans (or whatever they were called) and Snipers have near-identical stats, except the first cost less and the second are a national unit.
Snipers and Commandos have near identical stats except the first is cheaper, more powerful, and has a higher cap.
Stuff that probably isn't bugged but I dislike:
Arcology is spelled "Arcology", not "Arkology". My internet connection at the dorm isn't working well right now, so I haven't looked into it in depth, but there's a couple of typos. The biggest offender is "Infantrie Mobile", which isn't in English. That would translate to... "Mobile Infantry", I think.
The model for the cyborg looks horrible, IMO. I don't know any alternatives, but there's got to be some other model you can use. Maybe one of the BtS variants.
Mechanized Infantry does not upgrade further.
All your units need tips. Even short ones would be nice.
The name "Airwolf" is silly. I think it should be something like "Advanced Attack Helicopter" instead.
Stuff that I really want:
Actual flavor text for every new unit. If you want, I can volunteer to write you the text itself. It shouldn't be that hard to stick it in, right? (not very fluent in Civ4 modding)
Proper non-placeholder models for all the units. This I can't help you with, sadly enough.
I want a spy plane or two, with little attack power but low cost to do aerial recon. This could start off as a propeller driven recon plane, upgrade into the Predator drone, and then into the CtP2 style spy plane we know and love.
A few more infantry units. An interim one between Mech. Infantry and Cyborgs would be great-like, say, Exoskeletons (read up on DARPA's plans to field powered armor for US infantry within a few decades), much like "Infantrie Mobile" is a interim between standard Infantry and Mech. Infantry. And allow Mech. Infantry to upgrade to Cyborgs.
Or, as a potential alternative-remove Cyborgs as a unit entirely, and instead add it as an advantage that Gunpowder units can acquire from being built in a city that has a Cyber Lab. In that case, you could have some crazy future infantry, like hover infantry or infantry drones.
Gun-Equipped bandits after the archer ones-if you've watched a single Western in your life, you know why you need these in the game. Call them... Vigilantes, maybe?
Bandit Horse Archers should upgrade into its own tree of special operations cavalry.
Cavalry should upgrade to armor, not helicopters. Seriously.
A giant fricking robot or two, just because, in the vein of the CtPII War Walker.
Another unit I want that probably won't make it in, but hey, while I'm at it: Stealth helicopters. The Comanche is awesome. Have Stealth Helo as an upgrade alternative to Airwolf/the "Advanced Attack Helicopter", with lower attack but faster movement and some invisibility, and then have it upgrade to a "Stealthed Attack Drone".
Cyborg Commandos after Commandos, Snipers, and Guerillas. Come on, we need another upgrade step in the special operations tree. They rapidly become very limited in usage when Mech. Infantry show up, as those have twice the movement ability, lots more strength, and the ability to shoot at aircraft. When Cyborgs and nastier things show up, they're near-obsolete.
A Future Spy unit.
Modern/Future defensive structures. The CtP2 forcefield would be real nice here.
I also want some additional unit abilities that are only unlocked in the future. Examples:
Point Defense: -25% damage from air strikes, -25% collateral damage. Probably unlocked by either Microprocessors or Robotics.
Nanorepair: Heals 15% additional (for that unit only)-unlocked by Nanites, obviously.
Camouflage: Whee, invisible mode!
Urban Warfare: +25% city attack and defense, available for infantry units only.
Some more Modern and Future Wonders. And some more Modern/Future facilities and tile improvements, too! Some Ideas I have:
Cornucopia Vats (facility): increase food gained from all tiles, especially tiles that normally don't generate food (yay nanotechnology!)
Blitzkrieg (national wonder): add City Raider I to all armor units built, obsoleted by Antigrav.
Nanoimmune System (national wonder): Adds +health and happiness to all cities
Sentient AI (world wonder): Some research bonus, give "Combat I" to all drone units.
Probability Twister (world wonder): Reduces the chance of negative events and increases the chance of positive ones