The main issue I have about the evil path is the fact the goblins turn against you once you helped Minthara destroy the grove. You should be viewed as their champion rather. And yes, at least, give us Minthara as companion.
Another issue is with the hag. If you are so evil, there should be a way to conclude a pact with her of some sort so she can provide help later on in the campaign. I would love to get some redcaps reinforcements like the 3 ogres provide.
Of course, there should be some betrayal between evil characters. But it's too much in our face at the moment.