Why should a sorcerer wear heavy armor? It gives no perks for magic from what I see.
Same counts for warriors in light armor etc.

And can you switch weapons effectively in combat? Like changing staff to 2h or 1h FAST?

I tried to make a battlemage but was having a hard time finding it just as useful as a normal cloth wearing mage.

lvl 15 unlocks weapon swap, giving you the ability to swap between 2 different weaponsets

Can't really answer a lot of these due to NDA constraints. This is the wrong forum to have an in depth conversation on this.

This.