Name me one thing Custom Origin characters get that is unique to them? Other then their one origin skill.
I can list several things origin characters gets that custom origin characters do not get.
The XP is pointless to worry about; it might make the game slightly easier but it's not going to make the difference between being level 20 and 60 at the end.
It is the difference between being level 2 and being level 4.
Which is the difference between bumbling around the fort (especially on Tactition mode) and actually continuing with the story.
A single character gets an ability you personally believe is strong. What's your solution to that?
I've long since given it. Give custom origins a selection of 4 Origin skills.
Here are other solutions
-Give Custom Origin specific quests and storylines.
Or to sum up: "Treat Custom Origin characters as the game's 7th character"
Your post is too long to deal with effectively.