Perhaps it would be helpful to list all the things family gold are used for? I don't know them all, but I'll start the list and edit it as people add more.
Family support--family sends your (broke or nearly so) character gold.
Investment--boost production of the region you are currently in.
Pledge bail--family pays double the gold equivalent to get you out of prison.
Buy favors--lets you use smith/entertainment in a foreign region.
Fund rebels--when your family home is in a foreign realm, you can cause control to drop.
Add to bounty--entice an infiltrator to stab a hated enemy.
