2500 lbs RTB is plenty under most circumstances. Make sure you Ctl-J if your mission is over. This releases all stores including the hardpoints, but not your AA missiles

Also, if you're RTB get up to 27k+ and you could fly to Japan and back.
One thing you may want to watch is to try and maintain your energy; Get better at cornering speeds so you bleed less speed, only use the burner briefly to get back to cornering speed, and if you are running full burner to out-run something than just point your nose straight down and get the heck out of range.