One thing I would like to change back to v1.0: I want to be able to merge mercenary units, and also use them to replenish my regular troops (very useful after a bloody crusade has come to your province to leech off your armies). On that note, I wish the retraining worked the same way as in RTW: it takes too long to retrain units one by one, and there is no logical reason why you should have to.

For that matter, there is no logical reason why you can only construct one building at a time, either, and perhaps the number of buildings you can construct at the same time in one province could depend on population and/or infrastructure (and gold, of course).