Sorry for the late reply!

1. If you play "Casual mode" and still the AI has overwhelming army this means the mode is not active. There are 2 reasons for it:
- You have restarted the game which randomize player bonuses. This can change the AI mode. Always start a new game from the game lobby.
- Game mode depends on Player 1 setting so it seems he has not chosen casual mode. Just to be on the safe side set all players (human and AI) bonuses to casual mode

Edit this and try again.

3-4. Hero specialization "Pounder"  that granted first strike in combat has a bug that allows the player to wait and then be first and use abilities and spells. Specialization was removed but will return with next update as we will add a fix for it.

Regarding balance and changes.
Balance - Yes to some extent you will always go to Rock-Paper-Scissors type of game as outliers are found and balanced but have in mind that new content and mechanics have been implemented through the years and more will follow. Rock-Paper-Scissors is only possible in finite mechanics environment.

Changes - I agree that constant changes make something hard to follow, or hard to be liked. This is why we keep history on all releases on moddb so anyone can play the one he likes.