Must Have BLU Spells?

so i saw just how powerful BLU is for KI farming and well. i cant seem to find much help farming them so ill do that myself. with BLU. i plan to abyss burn it to at least 75 ish before skilling up and learning some spells.

this is where the question comes in. what are the priority spells ANY blue should learn first?

also any suggestions on spell sets for KI farming?

All of them.
I burned to 99 and capped Blue magic on worms using physical spells and skill up food.

Prothescar has a pretty good guide on what spell sets are best for what situations and also a guide for AoE burning on blu.
I really couldn't tell you where to start... so many spells out there.

Take a look at those guides though! They might give you a good place to start.

head butt, plenilune embrace, chaotic eye, enervation, magic fruit, quad. continuum, quadrastrike, heavy strike, amorphic skipes, goblin rush, battery charge, animating weil, cocoon, regeneration, charged whisker, whirl of rage, mp drainkiss, sheep song, sudden lunge, winds of promyvion, occultation, dream flower and blank gaze.

after that you get abyssea procs and then voidwatch procs.

learn the proc ones the rest dont matter

Waste of time to actually get all spells, for anything but plain completion. You will never need Terror touch as an example. Look through the spells effects, set bonuses, damage, and trait combinations to decide if Spell X is worth bothering with. The wiki's or proth's guide would be the best places to start looking.

There are just better things to do with your time than hunting down Hydro shot and Feather barrier. Probably. Can't hurt to get the junk spells, but I wouldn't suggest spending much time on them.

This is a subject that has been thoroughly covered in posts in the past. Give this one a try:

http://www.ffxiah.com/forum/topic/35116/blue-mage-spells/

If the reason for leveling the job is whisker burning, then you really only need to learn the spells for that task which shouldn't take too terribly long. You can be an effective burner with only a minimum of spells learned.

If you haven't read it, this thread will help.
http://www.ffxiah.com/forum/topic/20806/azure-lore-a-guide-to-aoe-burning-on-blue-mage/