Wow! Thanks for this huge list :)... took me a while to get all of this :)
You have very valid points - most of them (like wasd keyboard, skill readiness, balancing of terrain/units) we will implement into game.
For the RAM(charge) ability (scavenger warlord and footman) - it is intentional to ignore terrain effects on the path to target.
You can stun/exhaust enemy only if the height behind enemy is 2 and more.
Engagement is a special effect and should trigger free attack only when target moves, and only with some chance, so it's not always. The engagement icon should go away when the engager is not in melee range, if it's still there -> bug.
Units will retaliate if pushed against them only when: 1) is not exhausted, 2) is melee.
I've updated all description text in game related to your suggestions, and reduced the damage effect of spikes.
As for the Berserker class - he had 'grappling hook' ability - which pulls enemy to him, but we thought it's just too OP. He's still a candidate for re-design :).
For the ranged support - you probably right it seems to be OP, so we might add some mechanics to limit the effectiveness, like 1charge/turn..