are hashrates for total rig power? say if I have two rigs 800 kH/s each, which network should I stick?
If the two rigs are mining to the same address, then combined power. I'd probably go for 2nd network.
Are you sure the node will adjust difficulty to the hashrate? If not, both miners will get diff too high and will miss a shareblock.
I'm not sure p2pool nodes use diff adjustment extensively.
Not 100%, but either way, you should be fine mining on 2nd network with 800 kh/s I think.