Oh too bad that you dont have controller. Im sure your game on controller will be much more enjoyable.
About the melee, I was trying to force myself to use melee, through the dash etc but simple the ranged attacks and focus on dodging is much easier. Maybe there is no enough reward for melee attack? something like big first damage when melee hits with a lot of velocity. Or simply, nothing force me to use melee on a bosses.