Question: How do you tank?

[Canadane]

I thought tank stance was reduced damage plus a threat bonus? So the jobs just eat raw hits and only use cooldowns when swarming or against tank busters?

Paladins Shield Oath and Dark Knights Grit work what way. Reduce damage (both incoming and outgoing) while giving a boost to enmity.
Warrior works differently. They get an HP boost, a healing boost, an enmity boost, and reduced outgoing damage. But they do not get any mitigation on Defiance.

So a big hit is coming and somehow you've used up all your cooldowns. A DRK and a PLD could swap into Grit/ShOath and take less damage. A WAR cannot. If you're quick about it you can swap into defiance and hit Inner Beast, probably one of the best tank defensive cooldowns in the game. WAR has many options and it's one of the more versatile tanks.

As for shirk (not there yet but lv 25 now), that better held to a target macro or just targeting your mt and doing it manually?

I have completely abandoned any and all macros. Even macros for oGCDs may fail simply due to the way macros work in this game. I can get into more depth but my word of advice is to not rely on it, and work on just clicking your target (the party list works great for that) then hitting shirk. It sounds like it could take some time but once you have the swing of it, it's less than your GCD time.

Is there anything else I should be doing when it comes to taking hits? I went into the manor (lv 28) and dropped dead from the skeletons on the stairs (too much damage after falling away from the healer), losing aggro to the black mage and bard consistently even through provoke and the aggro chain I have available to me, and then dropped dead again during the boss fight when all the adds spawned in and demolished me through thrill of battle and rampart and having all kinds of trouble getting threat under wraps while everything chased the team around (mainly the dps) after getting raised.

I know for sure that was the literal worst run of the night...though granted the others were synced to the 31 cap, but I don't think I could grovel shamelessly enough to make up for it >.>

Provoke doesn't add any bulk of enmity. Do not rely on it to keep up on aggro. At your level, you're limited to a lot of Overpower spam and ....well that's it. WAR is very braindead at low levels, but gets pretty intense at higher levels.
As for dropping dead from those skeletons. Well... don't jump off without your healer lol. But that's just good experience you get from tanking. Learning those places inside and out, where's safe, where's hazardous. It's the best part about being a tank.