Just got the game yesterday, have a few questions.

1) Is there any means to open just the inventory part of the plate, and not the character stats/equipment? I assume not, but as it really obscures the screen when I'm trying to move things around etc, thought I'd ask...

2) One of the tips that pops up says you can't always fight, sometimes you need to sneak; in my experience that's rarely actually true in games, so do I need to bother with learning sneak or no? (playing on hardcore which I assume might make a difference with more monsters, please indicate if you think it might be necessary for hardcore but not other difficulties).

3) Will merchants offer to train you in things you already know? In the first battlefield I was offered pickpocket to 6 for 2000 gold; I already bought pickpocket back in the citadel, and I'm fairly sure it was to 10, unless I misremember. I don't want to waste 2k gold for something I already have.

Thanks in advance!