if it's only temporary....for the remote wire I would just run a small gauge wire from your positive terminal, directly to the remote terminal, with an inline switch. You'll have to flip it turn the amp on, but it's only temporary right? That way you don't have to touch your already run remote wire, you can just remove it really quickly.
As for using a laptop/ipod, yes it will work fine, there will be no loss of SQ, however most ipods/laptops don't have the SQ of a head unit playing a CD to begin with. Just guy a 3.5mm headphone jack to RCA converter cable and you're set. You will have to adjust your gains though, more than likely the preout voltage will be significantly lower than your head unit.