I personally find the Source Skills to be largely underwhelming. Yeah, some of them do massive damage, and could use to eat up one mroe AP, but last I checked Source Vampirism uses AP, so it's not like you can just pour out three source skills in one turn. Unless you use Time Warp, which I Admittedly have no access to because I'm not using custom characters.
Still, the most I really see needing done, especially since the ccharacters are -Godwoken- is MAYBE an increase in AP required to use the source skills. They already use a lot of memory (Sometimes too much IMO) and they're not gonna stay as consistently powerful late game (You'll clearly need to trade some of them out for better ones through act 2 /3.)
Overhauling the whole system... Well, it's probably way too late for that now that an official release date is out. But hey, if it really bothers you that much that a GODWOKEN has super strong skills then you can mod the game yourself after release and make things just to your liking!
Admittedly this is just me rambling a bit, since I still find the game challenging plus I find it a little reprehensible to eat souls and defile corpses just for a quick power boost when I'm not playing a full on vampire or literal monster of some kind. And I mean,t his -is- a role-playing game, after all.
