Sounds like you need a new sending unit. If something is wrong witht the float, don't try to fix it just replace it. They are a little pricey ($150 - $250 depending on brand) unless you don't mind dropping your tank again. These things are known to have wiring problems with age/use.
Trust me, I had my tank out of the car a few times in the last year or so. Don't try to save a buck, do it right and be done with it. You can test the pump out of the tank by hooking up 12V and ground to it and put it in a bucket of water to see if it pumps. One issue with this, these things can get weak and just hitting the tank will get them to start up again. But eventually they will stop altogether. So even if you suspect the pump is bad, may be a good idea to replace it while your there. good Luck with your repairs. LMK if I can offer any other help on this if you decide to do it. Really not hard to do, just take your time and follow all the safety precautions.