About armor system, lebrucht, u only played as 2, without any companions, right? All the problems you quoted only exist on that scenario, really. But its true that some of them exist.
1- You really cant do much when you are the only one that use magical CC, and have none else to do magical damage, but you can always support and buff.
2 - What? hydro doesnt have damage? I rly disagree... Maybe you are new into the game, but a solo hydro build with glass cannon and stuff and hurt, A LOT.
3- Magical damage weapons are great when that damage is also increased (elemental marksman for example), and it helps your mages break the magical armor.
4- Fire/earth mages are supposed to do damage, while water/wind mages usually have less damage and more CC, both will have low defenses, right, but thats about positioning, i couldnt care less for ppl controlling me as a mage, i almost always play glass-cannon xD
About stealth: It was like 1ap before, which broke the game, so they nerfed it a lot, but i agree it should be 3 ap, or just remove it on fights, it rly doesnt make sense to become a rock in a middle of a fight.
Two/one-handed: Yes, you are absollutely right about that, such imballance throughout the game. 2hande starts weaks, then just ramp up at act 2 and become ridiculous...
Dual wield is kinda OK, compared to the rest (besides 2h).
Mages do a LOT of damage earlier, then they rly fall behind late game... And yes, shields need to be buffed in all acts.
About memory: I rly like the system lol.