Just T-off and run the amp to both volume controls (LR and DR) then run your wires to each set of speakers from the individual volume controls. As long as all speakers are matched you won't have any issues.
2.) If it's a theatre room then I wouldn't bother with connecting it to the whole house. Since it's a theatre you should have a seperate amp, receiver, etc. running everything in there and have no need to connect it to the rest of the house since it will be used 99% of the time for movies. If you want to listen to music while in there just kick on your receiver and enjoy it in surround, just my opinion.