The only reason why a melee is harder to play than a sniper is because melee needs to move and use attack abilities, while a sniper most of the time has to do only one: move or shoot. It takes a little more effort to arrange the keybinds but once you are done there is nothing extea hard.

I started as a keyboard turning sniper back in december 2012, At that time melee seemeed so complicated. Then i switched to mouse turning, used some more elaborate key binds combos like shift mousewheelup/down and other, suddenly playing a melee class was not so hard after all.

The real challenge is knowing all other classes abilities, and believe me, MM takes some very good effiort to be a strong duelist given the insane amounts pf abilities that counter MM snipers.