Well I found out that the modified version of poclbm has been discontinued as a high-efficiency miner for bitcoinpool. So that answers that question. They recommend using Phoenix now (which I have already switched to).
But my earlier question about solo mining still remains. If I connect multiple miners to my "bitcoin.exe -server", does it effectively sum up all the hash-rates of the mining computers? Obviously this is how a pool works, but these pools have complex job-assigning and tracking software above and beyond the simple "bitcoin.exe -server".
Yes, that does work. The pools are all running the headless version of the bitcoin client, along with some other software.
Ah thanks for the reply. So I could essentially create my own pool with some friends by simply having them connect to my server... then keep all the coins!