I was wondering if I could be disowned, or quit, a faction. I ask this because I joined Redoran, but now I want to join Hlaalu. The console command "pcjoinfaction Hlaalu" doesn't work either.

Yes, you can be kicked-out of a Faction, if you murder another member or steal anything that belongs to them.
You can re-enter the Faction afterwards, but only once.

But you can only join one House. Even if you leave Redoran, no other House will accept you.

Dang it . Well, thanks for the help, Pluto. Edit: typos.