This is all good stuff. The only way to really learn is to try things out. It is true that also that it is a bit of a steeper learning curve when the skill gap is broad. But the game is mechanically balanced enough that player skill is the primary factor of most p2p outcomes.

Air/offense is a good starting point but really anything works if you have an at it approach to pushing your limits. Being comfortable bouncing back from death is the biggest thing to keep plugging it out. All melee classses but thief tend to work well in that regard across most pk ranges.