Special Units - You need to give me a updated list. Remember that suggestion? I do not remember... he listed many units on a table... I have to see it again after you modify it second to your.. (or our, dunno. Ah, since I'm technically part of the team, how influent I got? You know, I'm new to map editing and all. Even with teams, so.)
Abilities- Oh man, this is going to be big. You do not remember my gigantic suggestions about it at all, do you? Warriors on foot, armed only with a sword and shield should have aside of the crit/evasion thing (which they should have somewhat higher, since they focus on that). I'm not sure, but adding a more micro-able skill would be good? Or not? I was thinking on that we should add two abilities (Aside from some changes on some units, but the tendency is that). One passive and one active.
For example, the footmen. The extra crit/evasion (part of the footmen and as a form of balancing. If it is 25% chance for both, they would have 30%, or even 35% chance of both. A 10%/20% bonus in total. It could turn to 20% with a upgrade) bash (would be bashing of the shield as passive) and reduce damage (block). They are also the most fast attacker. And of course, it could also proper bashing (What I said about micro-able skill) that does some damage and stuns for 1 second, and 50% chance of receiving half damage as blocking.)
Archers would... hmm... I was thinking that they would have a good chance of crit, but no evasion at all. But they're actually light clothed with few health and armor, and would have a good evasion... but I'm thinking too elfish I think. Well, thinking well... their agility and marksmanship would be the passive. Which reminds me that the passive skills could be learn on upgrades. Well, it would be 50% crit and evasion. Or 40% crit and evasion with 3x crit. The active itself would be throw... YES! Such a good idea. Instead of throwing fire arrows and never throw ever again (just a momentary bonus to damage as they are spawned... not such a original idea) An archer would enlighten a fire arrow and throw it on a area. Oh wait. It would be better if it was for the hero right? Well, continuing. It would throw a fire arrow in a AoE, that would BURN. More damage to the buildings by the way, which would after the fire still get burnt with time. It would be a certain time or it would be needed to be cast away? Well, either way. Ah, I know. Don't know how to call it, but... the next shot will be worth 5x time damage (the archer would use 5 arrows at once). Also, crit shots are accounted, so if a archer throws 5 arrows at the throat of a goddamn knight, he's good as dead, yes. But that was a lucky AND managed shot. So.
A knight would move a lot faster, would be really high armored... and have a good evasion. But no crit, or only the normal one. Slow but great attack, the first hit counts. We could trigger something like this: they have 50% life or something of a normal knight, but after they "die" they would become a mixed footmen and knight skills [only the horse died] with some chance of the knight getting hurt when the horse fall. When you lead the horses near any unit military producer and they would get another horse. Well, the passive could be... that pulverize thing of the tauren (spears) and the active would be the somewhat already known charge (which auto use does not work. I am almost sure I am the only player on all players of LoE that have ever noticed it and use it XD. By the way, how the heck an attack speed increase will be any good if it wears off on the first hit?) increase movement speed and attack speed for 6 seconds.
Pikemen have normal crit and evasion, have greater range. They have that cleave (hits more than one unit, units behind the first). The spear men have lower range, and whenever they kill a horse, its knight always get hurt. And the tip of the spears are poisoned. (But poor knights! That's such a powerful counter!) Make poison not work on the knights, somehow. For the Crusaders: They're like a footmen with huge claymores. They do not have evasion at all, but have a good health and good armor, almost as high as knights. Their evasion is null or really low, and they have a 30% chance of doing crit x2 and 10% of crit x3. Passive would be cleave, and active would be inspiration. Something like avatar... but they gain great armor and vampiric attack. Passive could also be something like that, but when their health is too low, and the active to that would be... yeah, the rally of the knights would be good. But would be a war shout For The Light or something.
Special units... well, I need the list. And I think you would have 2 choices of heroes for each unit type. There were... Knight, Archer, Footmen... there was something else. Well. I think they would differ from agility and strenght, as far as I am concerned. One would be berserker. He would wield two swords, and aside from his abilities, he will have one more active ability and a avatar, and better version of the two already known footmen abilities (or not. If that is decided though, it would be default for all the heroes. But the skills would be a upgraded version of course. Or something similar.) his other active ability would be propably be... I don't know. The ultimate would be bladestorm leaving a bleeding effect on all the units affected by it. The other would be the Captain. One active ability would be... ok, I've been writing this the whole afternoon. My creativity just got overused.
Trade System: Check Solar Conquest. Could be that way, or every time you trade with someone, the wood/gold would just arrive on the beginning of the next turn, and depending on the current economy, it would cost more gold or more wood. Ahn... check Lords of Middle Earth.
Hero System: What you already suggested is excellent. Upgrade a normal unit into a better hero version of it. The only thing I want to add is the possiblity of two choices.
Edit: It will rise over time. I mean, the love. It is like that stability idea you had. The more time one owned a city, the less influence it would have. And I have answers for some of your questions...
A. Capturing city: A new method, like... something stands on a circle next to the city. Then after some time it will capture the city. It will give time for people to defend it.
B. Regiment System. AND a new command button: You produce a unit until you have 0 resources or full food.
C. They didn't liked it very much. I do though..
D. They didn't stated anything on that.
By the way, did you read my huge post? >_>