1st off: NIN's Extra Mudra abilities also act as Mudra resets, so you can skip the cooldown by using said skills, a feature I don't think much jobs have
2nd: DRG's Fang and Claw is a Combo ender that can only be used after your 3rd or 4th combo action. Also by that logic NIN's Armor Crush is a NIN action which means you'll be using a NIN action every few seconds
3rd: Seeing/knowing a toolkit and using the toolkit are two very different things
4th: DRG's Rip and Tear? isn't that GNB stuff