1 - first you are mining on p2pool mainnet, I suggest Jtoomimnet for BTC mining. Or at least find a node that seems to be more efficient than the one you are on. If no block is found, there is no BTC to payout to the miners. This isnt a PAY PER SHARE pool. You get paid based on blocks found and shares you submitted into the sharechain. So that means whatever your PREDICTED PAYMENT is at the time of a found block, thats what you will get for your mining work.

2- you will receive BTC when a block is found by the pool. Everyone is paid almost immediately after found blocks. The coins are generated coins that no one touches but your wallet.

3- p2pool pays the miners the founds blocks and transaction fees of that block. So normal BTC block = 12.5 BTC + extra transfer fees. Same with LTC network, just block reward is 25 LTC + transaction fees. Sometimes transfer fees almost make the block reward DOUBLE. p2pool, Kano.is, and Slushpool are the only pools that I know payout the transaction fee, in the BTC world. I could be wrong..

4- what you are highlighting is found blocks, but im pretty sure those are invalid? Not 100%, I mostly follow LTC p2pool. Like i said before, get off mainnet p2pool btc and join jtoomim net. More hash and smoother network.

Hope I answered your questions...and again, get off mainnet p2pool and join a Jtoomimnet node. ~80day est BLOCK time vs ~15-20days is a big difference. Not to mention the difference in block sizes between the two... LETS CRUSH BLOCKS!

-Keith