New Sony 7.2 channel receiver setup. What am I doing wrong?

I just purchased a new Sony 7.2 channel receiver for 200 bucks for my parents. I am replacing their 10 year old Yamaha 5.1 channel receiver. I am new to this so I am just going to provide you guys with as much information as I can. The channels for my new speaker are 2 front, 2 surround, 1 center, 1 sub, and 2 "surround back/bi-amp/front high/front b." My parents have 7 yamaha speakers which I am reusing. I have 2 speakers hooked into the "front" channels which are located right next to the TV. Three more speakers hooked to "surround" and "center" are on top of the TV cabinet (i know the surround should be somewhere behind us but I will fix that later). The last 2 speakers are outside on the porch which my parents had previously spliced together with the front or back speaker wires (i forget which ones). I currently have them hooked up to the "surround back/bi-amp/front high/front b" channels. Which channels would be the best for these two outdoor speakers that will only be used to listen to music outside?

Is it even possible to achieve proper surround sound on a 7.2 receiver even though only 5 speakers are actually in the living room and 2 outside?

While watching TV i notice that the sound changes quite a bit depending on what TV program is playing. It seems that some programs/commercials will play through all the speakers and some will not. Is there a setting that will force the receiver to play through all speakers even if the program/commercial does not support 7.2?

Hope you guys can help me out.

Thanks!