(quoted from post at 15:45:35 12/25/17)
Your question must be rhetorical... The answer is... No, plumbers don't use torque wrenches, their work is done mostly by feel, though, there is a rule of thumb, hand tighten plus two full turns.
There are a couple of types of fittings that we could be dealing with; Flared fittings, used in both hydraulic fittings and fuel systems. And, tapered NPT fittings...
I think for the most part, we'd see flared fittings in the fuel systems. In either case, using tape is discouraged, because there is a chance for pieces of tape to to migrate into systems and cause problems. But, in a flared connection, the condition of the flared mated surfaces is most important. Having a lubricant on the threads will ensure that it can be tightened properly. Torque, is an acceptable term to use... As it's a rotation force.
Tapered NPT fittings are a interference fit, where if they are machined perfectly, and lubricated, and tightened, it is theoretically possible for them them to form a hydraulic seal. But, since manufacturing techniques are knocking out thousands of parts in a run, tolerances can't be kept close enough to achieve that kind of result.
I personally like a paste, because it has the ability flow better, and seal imperfections in materials. But, again make sure everything is very clean.