I'm playing around with the less busy nodes, but still not seeing any payments even with valid shares being submitted. Rather confused.
Did you read how P2pool works? You need find pool share to get payout.
2014-01-01 04:53:20.107416 New work for worker! Difficulty: 0.025285 Share difficulty: 0.432620 Total block value: 50.000000 MONA including 0 transactions
2014-01-01 04:53:20.123149 P2Pool: 670 shares in chain (679 verified/679 total) Peers: 3 (2 incoming)
2014-01-01 04:53:20.123334 Local: 97034kH/s in last 10.0 minutes Local dead on arrival: ~32.5% (30-36%) Expected time to share: 13.9 seconds
2014-01-01 04:53:20.123399 Shares: 666 (25 orphan, 69 dead) Stale rate: ~14.1% (11-17%) Efficiency: ~127.0% (122-131%) Current payout: 3.9451 MONA
2014-01-01 04:53:20.123557 Pool: 122MH/s Stale rate: 32.4% Expected time to block: 14.8 seconds
monacoind getinfo
{
"blocks" : 6880,
"timeoffset" : 10,
"connections" : 94,
"difficulty" : 0.42252295,
"testnet" : false,
As you can see, pool share diff is now bit higher than coin diff

It will change in about 500 blocks.
Your miner is reporting anything over 0,02xxx but for payout you need 0,43xxx share.