[Suicide Junkie]

Tactical just won't work, because the SE4 UI does not support clicking on missiles.

Fighters are intended to not be able to fly through space on their own. They must be delivered to the combat area via carriers, or have the combat come to them, ala planetary defense.

Not being able to load cargo is bizarre; I presume you are familiar with the standard SE4 interface. Perhaps a screenshot would shed some light on your situation.
A savegame would let us try it ourselves too.