I think you shouldn't plan ahead to return with loadout. Just do your best to conserve as much fuel as possible during the flight in case of an unexpected situation and to get as much playtime possible. If you're on your way to the ship with way too much fuel that's ok, you can still dump the excess in the marshall holding pattern and get on proper trap weight.
Everything is moddable. Here it's mostly an interface problem. All they probably had to do is modify the pylon on the jet so that the missile can be attached and "talk" to the airplane.
Loading 3 x Mavericks per wing is actually realistic if you simulate an anti tank loadout of the 90s. They had 6*Mavericks total, 2*Sidewinders, ECM pod, a full gun load and nothing else.