I feel both bad, and a noob now :(
Noob, because I could barely kill him with act 2 chars, and bad for being marked as a solution ><'
I'll find the solution, I swear, and post it here >_<

Okay, I've opened the game, and searched the place:
For the bottom-left room, you will need a dark-magic spell, called "Whispering Shadows". It allows you to see secret doors. There is a secret door in the bottom-left corner, that needs a character with high might to open.
I think, the enemies inside it will give you the key for the NE door, if not tell me, and I find the key ><
(And the doors I mentioned earlier, the ones I was having trouble with, are on the 3rd floor...)
Sorry for being confusing, it often happenes to me that I try to help, and I just end up messing it up even more :(

I'd name it RPG of the year if no better RPGs come out this year.

Any help pls? Can't start act 2. The dialogue "TRAVEL TO ELEMENTAL FORGE" is not highlighted when i speak to the griffin master. Why????

You must activate the game on uplay to activate that dialogue line.