My big thing with Kath is that I want to figure out a way to make her ability come into play more often so I'm not just paying 5 points premium for 4 more pilot skill. Easier said then done but that's also part of the fun then isn't it.
Gunner and Marksmanship ? Seems about the best critical-inducing combination I can think of without resorting to one-use weapons (where, special ability or not, I'd far rather the target ended up dead than stressed!)