Best support: Barehanded - makes any weak class viable and helps conserve MP for useful situation.

Best action ability: Sword/Magsword/spellblade - Lets any physical attacker take advantage of weaknesses, combine with the ninja class dualwield and its a force to be reckoned with.

Worst support: MP+10%, thats a lot of work for a lackluster bonus.
or: Equip rod - really? who would choose to have a crappy weapon
on a better class?

Worst action: Control - never works