I can second all of these.  I am especially disappointed with diplomacy and wild lands.  Diplomacy is  almost useless to me, except to declare war and make piece.    Tech trading is far from intuitive - trading tech points is meaningless, and far from real.  You exchange skills, not some abstract volume of knowledge.  I mean, well, you can't give anyone half of the secret to making leather armor.  You either teach one how it is done, or not.

Wild lands are also a major disappointment.  You seldom get any meaningful reward out of it.  Much better rewards would be: unique, very powerful artifacts; unique spells, which otherwise would cost huge amount of research, or which are simply not obtainable otherwise; powerful allies; huge treasures of gold, crystal, mana.  The reward should be a game changer and allow even a weak player to stand up against the most powerful ones.

I agree with the following- the army size issue is big, because I think the game now is easier than 1.1 in some aspects, despite the AI being better, which I suspect is due to the rules changes, or me getting better at it.

The Wild lands issue is a big one- as it stands now, the purpose of wild lands is just to make their border more dangerous, and as a bonus stage for when you've won the game.