3) The pool software will be receiving a few tweaks to be more aggressively aware of botnets which have seen a resurgence since bitcoin went back above $3. This change will automatically enforce bans for inefficient workers. While there is some luck involved in finding a share from a getwork, efficiency should never be below 50% after a few dozen getworks have been processed, unless the miner is grabbing significantly more work than it can use.
Uh, looks like I need a new pool. My efficiency is always around 4-5% (using cgminer with one primary and two backup pools; the second backup pool doesn't offer merged mining).