Variance evens out when the hashrate isn't increasing exponentially. This isnt the case right now with rapidly rising difficulty.
Hashrate is increasing across the board. So variance will even out over time. Unless you have managed to find a pool that is not increasing its hash rate?
Most pools are increasing their rate so variance will even out.
Variance will even out for the pool, but not for you unless you increase your hashrate.
Variance always evens out. Unless the pool goes under or you quit mining at that pool. Now if you mean your hash rate does not increase but the pools hash rate does increase your share per block will go down. But the flip side of that is that the pool will be solving more blocks so you will be receiving the smaller share per block more often.
So if you invest in a miner and hope to get return, the first couple of weeks are most important for you.
If you lose due to a small pool's variance you may never recover, unless you keep buying more miners.
I think that you think this is a get rich quick scheme, or at least recover your cost's quick scheme. It's not, its a long term investment. The history of Bitcoin so far shows that you recoup your investment by the increase of value in Bitcoin itself.
Also I think your OP main point was that ASIC Hardware developers need to cater to P2Pool somehow. I think that responsibility lies with the Bitcoin Client developers.
The Bitcoin Client developers have been dragging their feet to make it possible to solo mine with ASIC hardware directly to the Bitcoin Client. If the client developers implemented the proper protocols in the proper way and added User Defined Difficulty then ASIC hardware could easily solo mine and "I think" that would help P2Pool out allot too. Maybe I'm wrong in that assertion because I'm not fully informed about P2Pool.
But I do think it is very import to be able to solo mine with ASIC hardware directly to the Bitcoin Client. That is good for the network as most miners have their local Bitcoin client as the last pool in their failover list.
Sam