1. Since you can switch skills around as you please outside of combat, I don't really see the issue with having separate, 2 memory source skills. Most of them are easily worth 2 memory. Yeah, losing that extra skill hurts, but there has to be SOME sacrifice to using source, considering they already can single-handedly win fights. Not going to use source in a fight? Then memorize regular skills.
If Source can just turn regular skills into source versions, then either you have only some skills that turn into a source variant, or all of them do. The former seems kind of awkward, while the latter is a ton of work and balancing. Or various different skills turn into the same source skill, but that's also weird.
2. In the demos, they showed examples where you could essentially choose to be stunned and take damage for 2 rounds to channel source into yourself in a "good" way, but I don't know if that will make it into the final game. Sounds difficult to balance, considering it seems like an infinite way to obtain source (presumably only usable in combat, requires nearby enemies or something). But perhaps they'll work it out.
I do think they kind of have the idea that evil characters will tend to have more source, but there will also be repercussions to obtaining source in an evil way.
3. Imbue source as a free skill (no need to memorize) sounds cool, though I think to some degree bless and a "curse" skill will represent imbuing source in a good or evil way. Now how about imbuing items with source? Basically a way to enchant items and balance crafting, since you're choosing powerful skills or powerful items. The effects should be somewhat limited, but noticeable. Say, there's a recipe that enchants your weapon to have a 10% to apply burning, poisoned, or bleeding. Fun and useful but not absurd. Or you could also enchant items to grant certain skills, so you'd be sacrificing source for versatility rather than power. Lots of options here.
