To address some of your points:
what is this useless and annoying shit?
Polymorph has access to some of the best skills available. Spread Your Wings, Tentacle Lash, Iron Heart, these are all excellent. Let alone the (extremely) powerful Skin Graft.
Elemental Totem, One-shotted by ennemy
Don't put it somewhere that it's easy to hit (this
is possible). Totems can be high Damage-per-AP casts if they are given a few turns. That being said, there is more reliable damage.
So as I'm smart, I buff him with Armor of Frost & Fortify.
Clearly the additional armor you've given the totem is not going to allow it to tank. How silly would it be if those spells were indeed this powerful? You may need to rethink your positioning.
I have a rogue completely overpower with Haste, Adrenaline, Skin Graft, Enrage, Flesh Sacrifice, with some other spells for mobility like Teleport, Tactical Retreat, etc.
It is true that Adrenaline + Flesh Sacrifice + Skin Graft is overpowered. Enrage does nothing for a rogue who is already backstabbing, though. Still, this combo is
absolutely not required to dominate the content.
No doubt you will be obliged to play this way when the superior difficulties come out.
If you approach the game with this attitude, probably.
The pawn, Mnemonic etc ...
Pawn is far too powerful, I agree. Mnemonic is nice, but is a low-priority talent compared to others.
My melee character hits an electrified or burned target and he finds himself to undergo electrical or fire damage.
This is awkward, I agree; mostly with electricity. However you can avoid this problem with Spread Your Wings or Winged Feet. Or simply Magic Armor. Surfaces very rarely pose a large threat to a prepared player.
... Ridiculous. Especially as the mage has 15 action points in the turn. Remember my Summoner & polymorph had only 4!
That player skips the first round. The AP/round on the character is 5, one is from haste. Again, it is clear that Adrenaline/Flesh Sacrifice/Skin Graft needs tuning, but this should be expected in an early access.