Mike,
You can power two pairs of speakers with it, but they will output the same audio. In other words, if you are trying to do surround sound, the rear speakers would be playing the same thing as the front speakers.
If the inputs are identical, then you can hook up three components that are not a turntable into the following inputs: (1) AUX, (2) TAPE1 PLAY1, and (3) TAPE2 PLAY2. Like TLS said, the phono input has a different (higher) level of amplification performed on the input signal, so you don't want to plug anything but a turntable into the phono input. If you did, the result would be that the sound coming out would be really loud.
So, you could hook up anything that has the two-channel left/right RCA analog outputs to this, such as your TV and DVD player.
As for using the Pioneer 950 bridges, I would expect that those would work as long as they fit between the PREOUT and MAIN IN jacks. Otherwise, I would think that any cable would work as a connection. If I understand TLS correctly, you just need those jacks to be electrically connected - which you could do with any cables with RCA jacks on the ends. The bridge connectors are probably just more handy because they are compact. I'm sure that I'll be corrected if that's wrong.
Adam
EDIT: I took too long to type. I see that TLS has already given an answer on the jumpers, which (lucky for me) agreed with mine.
