well, you can expect to get steady payments. You should get all your coins sooner or later

it all depends on rate of finding blocks and stuff like that. Keep in mind that all those numbers are fixed values of shares and payouts are affected by founding a block. Which means slow blocks slow payouts, fast blocks fast payouts.
it doesnt really matter on which network we mine, in the end we will get same payouts everywhere.
you will get paid as long as you have valid shares in database, even if you are not mining. You should probably, as everyone else, read how this payout system works
http://eligius.st/~gateway/faq/capped-pps-recent-backpay Might shed some light on your situation

Just to make sure I'm getting this right, on a merged pool there are thus two levels for the VTC part: at the p2pool level a single address, the node's address, is being paid the VTC using PPLNS, while at the proxypool level that payment is redistributed using CPPSRB?
And the MON part is basically a "pooled" solomining redistributed using CPPSRB, which will only be payable once a block is found?