Can you mine other altcoins or pick the pool such as multipool?
Yes you can throw the power at any pool you would like.
Edit.
I am currently mining on multipool but I am about to switch. My Mhs seem to vary greatly on multipool and it makes me wonder where its going. CG miner throws both my cards @ 770 each but sometimes multipool is only crediting me for 900-1300 khs. Poolerino seems to give me a stable 1500-1600 khs.