Now, this get's my blood flowing

do i need to start new game for it to work boss? if so is there an event I can kick off to give traits on existing families plz. really don't want to start new

Yes, I cannot guarantee the character creator, but hear issues.
You can indeed form more bloodlines, and take multiple from the Character Creator.
Forming multiple bloodlines through the event gets increasingly expensive, but should you be able to afford it, you can indeed create multiple bloodlines through game mechanics.

Thank you, so help me understand this please as I think it's wonderful.

If I take a single blood line 'trait' from this mod in character creator, all of my legitimate descendents will inherit the trait?
and I can have more than one?
and I can still form my own 'bloodline' through the normal game mechanics.

Are those correct assumptions?

Skulls for the Skull throne.

Blood for the Blood God.