A:AnswerNo you can't do that unless you want to smoke the amplifier section of the receiver. Just hook on speaker to the Left main, and one to the right main, and use your pre-amp sub out plug and go.
Just because your speakers are rated for over 145wpc, they will should play just fine with the power this receiver has.
A:AnswerIt does not have a phono preamp so unless your turntable has a built in phono preamp or you are running it through an external phono preamp you wouldn't want to connect a turntable directly to the receiver.
A:AnswerI have not used anything bluetooth on this at all. It should work fine, but I will leave that up to someone who has it configured that way. Keep in mind though, Best Buy does have a great return policy if it's a no go... Take care~