Will this amp work for this?

I have a kenwood kac-929, rated at 460 rmsx1 @4ohms bridged. My question is can i run a 12w7 off this amp until i can get a bigger wiring kit installed to hook up my 1000/1? W7 can either be wired to 3/1.5 ohms, and my amp can be run at 2 ohms or 4 ohms? And it can be bridged at 4 oohms...will it work, and if it will how would i wire it, just bridge it and run it like that?

If the sub is 4ohms and the amp is bridged then yes, you can use that amp with that sub. If the sub's impedance (ohms) is lower than 4ohms then you cannot bridge that amp and use it with that sub. The amp will more than likely go into protection mode whenever you crank up the volume because the impedance is too low.

Can i use only one of the channels to power the sub?

Yes, but why would you want to?

Just to test that the sub works and is not blown when i get it, until i can run the 4 gauge to run the 1000/1...

dont run a single channel to the sub its pointless, I agree with the post above, if you have the option to run a w7 then dont use a kenwood amp. kenwood is nice entry level stuff, but if you want real performance go to a 1 ohm stable amp(kicker,PPI,high end rockford, etc...) that way your not fully maxing out the resistance load and have less of a chance of damaging your amp or sub.