You can usually start off your encounter by flanking the enemy to get your damage bonus then stun with leg sweep if need be to reposition yourself. Once you get Spineshatter Dive, you can use that to stun and reposition yourself as well.
As for increasing damage of melee DPS, I think that would be the wrong way to go, not because it's a bad idea, but because it would make the game easier than it already is. Lowering ranged damage is a better solution IMO.