I bought mine in the store, but it wasn't with the normal PVC fittings, it was near the sprinkler and drip system fittings.
Sometimes the hose male is to short to fit properly. Add a second hose washer. Please, be careful not to over tighten. easiest way us to hand tighten, then turn 1/4 turn with pliers. Turn on the water, if still leaktng, turn until leaking stops (not to tight). Carefully check that its not the garden hose that's leaking. Cheap hoses have bad crimps on the metal hose fitting around the hose. Usually you'll see water leaking out at the seam (indented line) between the hose threads and the crimp. Hope that helps. ;)
If by bib you mean the threaded part of a faucet or male end of a garden hose. Yes, any 3/4 inch male hose thread will fit.
mine is set at 60 psi
The slip end is designed to accept tubing, not another fitting. Some times you can find a "street" fitting (usually only on elbows), that allow one fitting to fit into another fitting.
Yes, the male hose end.
Please be more specific. How would you improve his fitting. I am sure the manufacturer would love to know so would Home Depot and myself.