A Blue Mage Beastiary

[shintashi]

Some Common Blue Mage Enemy Attacks and Who might have them

Blood Drain - Bats have it, heal and damage at same time
Goblin Punch - non-elemental attack, potency considerably higher if target same level (very effective against fates and end game targets); Goblins tend to use Bomb Toss instead and the equivalent of this in FF14 is Goblin Rush, which sucks by comparison.
Aqua Breath - Area effect Water Attack. FF14 doesn't really use elements so this is just an animated AOE attack.
Bad Breath - Morbol type monsters have it, Cone AOE that does status effects, severely powerful
Doom - Eyeball monsters have a variant, like Ahrimans. This could wreck weaker enemies if it worked, so its probably RNG or max HP based.
Level 5 Death - i dont know anyone who has this but all end game monsters say level 50 most of the time, so any "specific level" powers either always work or are too powerful for this MMO, because they would work on virtually all end game targets. Although, adding Heavens Ward levels means not everyone would be level 50 anymore, so the balance might be restored.
1000 Needles - Cactaur variants have these. This is a Blue Mage Must.
Fleece Butt - Sheep. People Want this. Makes a good low level filler ability.
Death Claw - probably does DOT instead of reducing target to single digit hp, learned from the Claw monsters, and paralyzes the target during the DOT.
Osmosis - This is a blue mage ability from FF11 that steals HP and copies 1 status effect currently on an enemy. This type of power could even be a standard Blue mage power, such as a level 32-50 ability. There's an ability similar to this used by Leviathan to copy and use your attack against you. That kind of thing is totally Blue Mage territory.
Jettatura - a Blue Mage ability from FF11 that also appears on one of the S class hunt enemies, I think.

[Jonnycbad]

There would only be a few spells though considering how crazy their hotbar would be if they had the same number of spells as in XI. You'd have to learn them from leveling or through quests, or otherwise have basically nothing to work with. Perhaps a trade off could be that BLU could equip any class equipment(anything LNC,GLA,MAU,PUG,THM,CON,ARC,ROG, etc) but nothing job specific(nothing that's DRG MNK PLD etc only i.e AF armor). So you could have a full heavy armor BLU with dagger or something. This would allow BLU to be flexible in combat at low levels before they learn many spells, the trade off to being able to equip all this is perhaps reduced stats in the opposing type, so if you equip heavy armor, you get bonuses to HP and VIT but you get reductions in INT and MND, so depending on what you equip different spell types will vary in potency(some spells might be based on STR/DEX, magical spells based on MND/INT, as BLU has always been kind of a combat mage).

[shintashi]

Jonnycbad - One of the solutions I came up with to avoid Hotbar Flooding was to basically double/quadruple the "Additional" Actions from 10/5 to 20, but also lower the total number of core job/class Actions to 8. See, almost all jobs have exactly 28 actions by the time they hit level 50, so If BLU has 8+20, they meet that criteria. An expansion for BLU above level 50 could likewise have more additional actions. For example, if 60th level heavensward classes have 33 actions (5 more than normal) then BLU might have 8 core +25 additional slots to fill.

The remaining group of Actions remain dormant, like unassigned Crafting Actions.

Additionally, your idea on the Gear Slots I mostly agree with. I suggested a wide birth of weapon choices, and even noted Gatherer gear might work. We could even trade out jewelry or offhand slots for additional Traits that add Monster style bonuses to defense or stats.

[Wintersandman]

You could always macro abilities so that one gets used if the other is on cooldown.

[m3eansean]

I hate to be a wet blanket, I really like BLU in other games. But the way this game works, they can't have a viable class that learns skills from enemies. They are super over the top about balancing. BLU if it were here, would had a very pre-set amount of skills (no more than the other classes due to balance) and they would perhaps have names of skills similar to beasts in game, but that's about it.

I wouldn't get my hopes up on seeing the ability to "learn" really cool skills from extreme endgame encounters, just wouldn't balance at all and be a huge detriment to the party when certain BLU's wouldn't have X OP skill.

If the BLU was in this game, I feel it would be much like SMN in the sense that it is NOT what everyone expects it to be. Just another DPS rotation with some flavor on the skills to make them appear like skills of some beasts in the game. I don't see the swapping in and out of multiple skills working at all and it would be a huge diversion from the path this game has taken.

[KikoriL]

I personally picture it as a temporary copy of the different tiers of attacks monsters give. Trigger an effect that "learns" what's hitting you, save the blow's details for use by filling in the variables of X for Potency, Y for Aspect, Z for damage type. Random examples...
Off-GCD melee attack slots for: Something like, as posted earlier, Fleece Butt. 140 potency, no aspect, Blunt damage type. Withheld for 60 seconds or until a new skill is learned.
Standard cast spells for: Something like a Sahagin's Hydroball. 165 potency, Water aspect, Magic damage type, additional effect of (I think) silence. Withheld for 60 seconds or until a new spell is learned.
Ultimate spell slot for: Something like Heavensfall. 350 potency, no aspect, magic damage type, additional effect of knockback from the aoe's center. Withheld for 60 seconds, until a new spell is learned, or the spell is used once.