Here's my take on the subject from someone who's been a mechanic of one sort or another for 50 years the last 32 before retirement as an industrial maintenance guy. The rule of thumb I go by is, the threads need to be clean on all parts, and should thread on close to 2 turns before starting to bind up. I would never try to put a pipe threaded joint together without some kind of pipe dope or tape, if for no other reason than it serves as a lubricant. In this case I'd go with something advertised as being fuel safe. As far as how much to tighten goes I agree that you need to use the shortest tool possible and keep your hand close to the fitting tightening the whole assembly at once. Once it starts feeling tight bring it around the last part of a turn to where the fitting needs to be pointing. It is a matter of feel as to if its tight enough but if it leaks although its a pain you can always tighten more or take it apart and do it again if need be.
