On that note. I been doing solo mining by renting rigs but when I'm not renting, i do have cpu miners going just for that wild chance. I know when I do these cpu miners its likely nothing, but I didnt know I could be harming the pool? If so I will stop.
It's not 'harming' the pool, as -ck said it is just a waste of resources because it uses the same amount as a miner that has at least a remote shot at binding a block. It all boils down to the miner being fast enough to even process *one* share.
Remember,
on average a block is found every 10 min and new work will be generated when it happens. That means that your miner MUST be fast enough to process
at least 1 share in that time. Even at a suggest diff of 1 using CPU's are unlikely to do that so on every point it is a waste of resources.