Usually I think it works out cheaper to buy a submersible pump than rent. You can get one from Harbor Freight. I wouldn't have any idea what size to recommend, though.
Re: No need for a bucket test...it's a leak
Check for tiny pinholes in the cove area (where the floor meets the wall). I have a leak, and that is what my problem is.
A patch could be overkill, but patch kits are relatively cheap, so why take a chance? Here's one for $10 on Amazon. http://www.amazon.com/Hydro-8815-4-Ounc ... +patch+kit
Sometimes Craigslist has good deals. I don't have any experience with pool supplies, but I did buy a truck through Craigslist before and got a good deal.
I believe those may be spider mites (same thing as clover mites, I don't know). I don't have a pool deck, but I do have a cement retaining wall with them that I sometimes use as a seat. I have never had a problem with them biting, so I always just leave them alone.