If I remember correctly there was previous feedback about DoS2 being origin focused leaving custom pretty lackluster. They already took this feedback into consideration and tried giving customs more. Origins currently can't change race or background and probably other stuff. Dialog goes by tags so you'll run into lines for race/class/background/deity and originating from Baldur's gate which you can not change. They have a good amount of companions but if it bothers you, you can always get Hirelings early on after first dungeon or create multiple custom characters.
Truthfully I'd recommend just picking something you like and sticking with it at least till end of act 1. I put roughly 80 hours into just that act and there is tons of content well worth the time.
