Kills/sortie means little because often the most shameless runners will have the highest K/S.
Look at it whis way....if you fly around for 2 hours and find 2 clueless dweebs who never see you comming, you land with a K/S of 2.
If you take off and immediately get jumped by a pair of high bogies, and manage to dispatch them, then land, you also land with a K/S of 2.
Which pilot worked harder?
Granted, you might say that a vulcher who kills 8 or 9 enemies on the runway is being unfairly rewarded, but in truth vulching is pretty risky. Not only do you have to brave ack and GV fire, you leave yourself low and slow and vulnerable to any high enemies who show up. It's certainly more risky to fly around at 100 feet dodging flak and GV fire, than to fly at 30K and do nothing but pounce on guys 10K lower than ya.
All this matters ONLY if, for some reason, you care about anyone's score other than your own. Because of the quirks you point out, it's pretty clear that score is NO indication of relative skill. This is why most people choose not to worry much about score--it truly is meaningless.
It's good that AH's score system rewards people who find action fast. The absolute leas thing you want to encourage, from a gameplay perspective, is running. An arena full of runners is a very boring arena indeed; the "perfect" arena will have some balance between the "furballers" and the "runners" .
HINT A: Want a GOOD fighter score? Try the following: Goon a base for capture. Once you get your troops out, ditch the goon and get airborne in a fighter BEFORE your troops take the base. If successful, you get credit for the capture in your fighter score and your fighter score should skyrocket. While I've never done this personally (I care nothing for scores), enough people have to leave no doubt that it works. Ironic, isn't it, that to get a real good fighter rank it helps to NOT fly a fighter?
HINT B: Overall rank is determined by a mix of your fighter, bomber, and other rankings. Hence, if you spend 100% of your time in a fighter, only your fighter rank will improve and your overall rank will remain low. To get a really good overall rank, do a variety of missions.
J_A_B