Played it a decent amount of time.
What can I say, I love it for most of the part, you've done a wonderful work.
The system works well and it's not that much unbalanced, as you can make skill combos as deadly even in vanilla, so not really a problem if you know what you're doing.
Plus, I started another run right off at Epic difficulty (using Defiler) with a level 40 Hero, so I had much more skill points and attributes to spend, but in the end it doesn't really make a difference, because as said earlier, if you know what you're doing and what build you're looking for, you can basically break the game even in vanilla.
My opinion is that this mod it's already in a fantastic state, and doesn't needs to include edits to difficulty to buff monsters or nerfing skills at all.
Very good mod, great idea, recommended to everyone basically.
Thank you Nargil