Ok, here are some idea's

-would like to be able to save my better campaign battles in the form of a replay.

-I would like the options of ransoming,killing the ringleaders or mercy back, also I'd want to have the option of killing enemy prisoners at the time when the battle is still in progress ( so you can cripple your enemy even If you might lose the battle )

-a Glorious achievement mode, GA, or an improved version of it - suggestions?

-I'd like to see the historical units or Heroes come back from Medieval Total war.

-To be able to wipe out factions with assassins in the mTW style, however balance it so that it isn't as easy as in Medieval but not as impossible as in Rome.

-Larger battle maps, which have more details on it ( think different sorts of terrain etc. ) and can actually be the difference between losing or winning a battle.

-Better weather effects + the corresponding penalties or bonuses, meaning archers have a decreased effectiveness in the rain, camels get bonuses in a sand storm, decreased sight in fog ( think fog of war ).

-Supply lines, which I incidentally did see in a Rome total war trailer / screenshot.

-Make retraining harder, aka make it take as long as is necessary, so given a unit is 100 men strong it should take longer retraining if it has 20 units than that it should take if it had 90 units.

-You shouldn't be able to load a full stack in just one boat, I'd rather have the Medieval system of naval transportation than the Rome one, which says a lot.

-Make certain strategic positions a priority to defend for the AI, meaning that the AI should cover bridges or mountain passes or built castles / forts in those area's.

-An improved diplomacy system, catholics should have an easier time negotiation with fellow believers than with Orthodox or Muslim factions and Vice-versa.

-Armies should be able to cover more distance in your own province than in enemy provinces ( Stolen from another thread, Thanks )

-Rebels hunting should not take more time than fighting battles against the current enemy super power.

-Civil Wars need to return, period.

-Alliances should be there for a reason, and allies should help each other if one of the factions in that alliance ask for help, also backstabbing or cancelling an alliance at a very very bad time for your ally, should result in a loss of ...prestige or influence , loyalty or something of that kind.

-Make the AI form armies rather than 3 unit border patrol
Meaning it should form stacks rather than forming various little armies.

-AI armies should always be led by a general - that general would NOT have to be a family member.

-Bring back the feature to assign titles to generals, governors, maybe expand that feature - suggestions ?

Well thats all I could think of at the moment.

Will maybe edit this thread of post new brain waves in this thread.