Yes, but how much really do you use real transactions within your family?
If the environment isvtrusted, just have a go with a credit-debit system based on relationships. If I've a debit with my uncle of 50 bucks, I'll pay it back the next dinner by paying also for him. You don't need real asset istant settlement in a relatioship-based credit system.
IF trust is not an option, then there is no point in using ecash, because you cannot trust that the mint will enforce the "21mln limit".
Sure, privacy is still a matter, but really is it significant to assume that Uncle Jim custody schemes will need to use strong privacy techniques? And is community custosy in the form of " uncle Jim custody" significant in the context of the broader bitcoin ecosystem?