Well, I hate to say it, but don't expect additional reward without additional risk.
I am not an elitist by far. I don't beleive in nor espouse "If you can't take the heat get out of the kitchen" mentality, but seriously, there is no need to play the game on anything but normal setting, in which I have never had an injury. Sure, Advanced mode will get better rewards, and Elite will get still better. But I have never had a critical injury in Advanced mode, and I also am not good enough to even consider taking elite by myself.
You can get basic and major kits at Starbase One for not a lot of money. Lookin at it from a pure economics thing, I have paid for all the healing kits with with first blue items I picked up and sold.
To me, Advanded is the "challenging" solo mode, and Elite is there to push multiplayer groupings in a mission.
1) STO didn't automatically set difficulty for all your officers to Elite.
2) Minor injuries do not heal (100 hours logged and counting.)
3) There would be some sort of cool down ability that you could use to repair/treat an injury. Even if it's once every hour played, it would be welcome.