[Guide] A basic primer on party play and dungeons

[Soukyuu]

This guide is really helpful, thanks a lot.
I wish there will be more examples for DPS & the shorts used in doungens like 'Adds', that's right I didn't know what it means untill now.

Adds stands for "additional enemies", which should be killed off as soon as they spawn for different reasons. For example, too much damage to the tank, mechanics like boni applied to the main boss if adds not killed fast enough etc.

As an Arcanist I mostly use Emerald Carbuncle because Topaz seems to get get in the tanks way. Summons gain enmity correct? So as Carbuncle is casting "Gust" do I also gain enmity from the attack as well as my summon?

I'm trying to learn the nuances of this class so I can be a helpful and effective Summoner eventually.

Pets are treated as a separate entity, so their hat is not your hate. You can use Topaz if the tank doesn't seem to handle hate well, just make sure to position it so that it stands in the same position as the tank. Otherwise the shifting hate will cause the enemies to turn between topaz carbuncle/tank, messing up melee dps positioning and reducing their damage.

Holy crap! I had no idea that regen hate was even a thing o.0
Granted, I don't yet even have the spell or the job, but that's a big change from what I'm used to. Also, in a situation where healers have been smacked around pretty hard, would it be better for them to regen themselves slowly back to full hp than to drop another hate spike of a cure?

It depends. Regen is building hate slower, so if the damage you are getting is not that high, it's a better option. On the other hand, in boss battles you might suffer sudden spike damage, risking death if you are not full hp as fast as possible.

Also, Regen is only an option for WHM, SCH only get a regen on the fairy, which is an AoE version on a longer cooldown.