A:AnswerMake sure your speakers match the specifications of the receiver. Sounds like you are overloading it and it is shutting off to protect the amplifier.
A:AnswerThis receiver connects to source devices using the red/white RCA audio connections which should allow you to connect this to your TV. The stereo then connects to speakers using speaker wire, which you can use to connect the speakers to the unit.
A:AnswerThat's a real problem. Unplug all of your audio inputs and see if the hum is still there. If it is, you will need to exchange your receiver for a new one or fix the one you have. This hum normally comes from a ground bounce from your audio inputs from things like a cd player or other audio component. If you find the hum coming from one of the other components, then you can blame that. It is unlikely a speaker issue with normal speakers.