I love your no. 2 and 3 ideas, I can see many good things coming from those ideas. I agree with Prolix about the first idea, there shouldn't be too many perks to joining guilds, because sometimes people just don't want to join, they shouldn't be punished for it.
As for the individual houses, I'm not sure. I mean, I like the idea, I'm just not sure if it will work. What might work is if someone wants to rent a shop for example, to make it fair you have a fixed time limit on the lease, so others can use it too for a while. Very rich individuals may be able to buy one, but I don't know, we'll need the devs input on this one.