That's the idea.
Have a look at this design journal to see the current mechanics intended for families / bloodlines.
It's safe to say that everything you want in your OP is already planned for the game. Every player will have a family as part of one of the two progression mechanics (the other being skill ramps in souls), and you will be able to set an heir to inherit your things when you die. That can be a child or another relative, I think.
I'd recommend going through the design journals, since they pretty comprehensively cover everything planned for the game (as in, if it's not in a design journal it probably isn't going to be a part of the game)