Cross Job/Class ability question

[Satyr]

I recently reached lv.30 with my Archer and I would like to grab the Bard job. I know that you need to have a lv.15 PUG to be able to unlock the quest. I also know that Bards can use Lancer abilities.

Other then that I am kinda confused.

Do you have to lv. Archer, pug, and lancer to their respective ability levels to use them as a bard? Blood for blood for example is a lv.34 Lancer ability that bards can use.

This would make sense but their must be some sort of level requirements.
i.e. a lv.30 bard couldn't use blood for blood.

I've been looking (google) for a detailed explanation of the armory system but I cant find any good info.

Any help would be great!