Now you just place a typical PPLNS framework on top of your node. People register with a user name. When they connect with that name, since it's not a BTC address, their hash rate gets added to the node's default address. Now you have all of this hashing power on one address that is contributing to the share chain. As soon as a block is found, that address is paid. Then, you just divvy out the payment to the miners based on a standard PPLNS system.
That does nothing to solve the lost work due to the short p2pool share time.
No, it doesn't, and I didn't state that this would address it. All I stated was how you could put a traditional PPLNS payout framework on top of a p2pool backend. The frequent restarts... now there's a problem that needs solving, and I'm not sure Bitmain has pulled it off. Will certainly need to see what they're attempting if/when they actually do drop their source code in github.