I would guess all your problems have been caused by one thing, Ethanol. This stuff is down right bad, it eats through lines seals, and messes up stuff real bad. The issue of getting no gas when you try to prime the line is probably being caused because there's a hole or holes in the gas line which is causing air to get in and preventing it from forming a vacume to prime. I would go to your local hardware store and ask for an Ethanol resistant fuel line, the one I got this year is named Tygon and costed me $.85 for a six inch piece. I would change out your fuel line and see if that fixes the problem which I'd bet will. Also you can check the fuel tank for leaks real easy. All you need to do to check the tank is lay the auger in a position where the gas level is below the outlet (where the fuel line connects to the bottom of the gas tank), pull off the fuel line, press your finger firmly against the fuel outlet, stand it up, and see if it still leaks. If it does not leak the problem is your fuel line but if it still leaks the gas tank has a leak in it.