DoctorYO You apear to be only looking at one side of the equation.
What K/T realy is , is agresivness, In the real world accomplishing the mission was a huge part of the run/fight dissicion making proccess. With out it, why be agressive, why not just pick and choose your kills, and alway run when at a dissadvantage.
Take a look hartman: The resone he is viewed as one of the best is because of his K/T, i.e. he killed the most during the time of the war. Infact I belive there are quite a few other pilots around with a much better K/d. The resone he had a great K/T is because he was agressive. Plus he mostly doing the exact opisit of what you wish to promote, "Deep missions" I belive most of his kills came with short defensive missions.
So changing K/T would not make things more realistic, but wrather would make it less realisitic.
2nd.
Most people don't wish to admit it, but most people at least look at there score, and changing the score system affects game play greatly in the arena.
I've seen examples of making K/D to high, it completly changes the way people fly. Suddenly attacking only happens when the player is very sure he will not be killed. When everyone is doing this at once, what you end up with is everyone running all the time, and very little acm. In fact it even promots vulching, because that is the simplest way to get kills with out much risk.
3rd.
You realy can't game the game with K/T because consentrating on it alone will lower your other stats. I.E. Beeing to agressive gets you killed.
As for you non scorring items you brought in, thats a completly different discusion.
HiTech