I've completed ToB once, with a neutral/good party. Was wondering if there were many diferences if you go through with an evil/neutral party, as I'm doing this to romance Vic in SoA

SoA (now)...
Me = CN asasin
Vic
Edwin
Korgan
Jan
Anomen (failed)

There isn't really any difference in how you treat the other bhaalspawn. The main differences is in the pocket plane and at the end - you will no doubt give Solar evil responses when she talks to you after you kill each Bhaalspawn, and then the encounters in the pocket plane areas are different. Then the choice you are given at the end by Solar is different as well.