My solution to the current exploit of dying to get xp.
The solution is simple: have a prestige rating that is based on your kill/death ratio. For example: at the end of a match if your k/d is 4/1 you gain 3 prestige points. If it's 0/4 you lose 4 points. Say you can't go below 0 prestige so as to avoid the problem of a newbie losing over and over. Also reward prestige for taking capture points in salvage and for healing.
You could do many things with this score but here are some of my ideas:
1) Have a leader board. Nothing prevents people from exploiting better then the scorn of their peers. Also allows for bragging rights.
2) Be able to cash in prestige for bonus stuff. Say medals or xp, or special gear or trinkets.
3) Get a 10% experience buff for say an hour or two.
So your solution to people who dont care about e-peening and suicide a ton is to...
appeal to their e-peen?
Well if there are good xp rewards for it, or special loot that you cant get without it, at least it rewards people for actually trying to be good. Those guys can still do what they do but they don't get the other stuff. It doesn't stop them, but it does reward players who want to actually do well.