A bunch of questions

[Niwashi]

7. You listed them all. But at Level 50, you will gain +50% EXP from FATEs for below Level 50 on any class. That may require finishing the first part of ARR's Main Scenario to unlock, but it's permanent.

Is that one new? I don't remember seeing anything about it in patch notes.

[Estellios]

In case the op still checks here, concerning being a squishy low level tank:

• Make sure the gear you are using is intended for tanks. There are several equipment sets that tank can wear but are intended for DPS so stay away from stuff if it lowers defense unless it's a significant item level increase. There's now a "equip best gear" button on the equipment screen that basically does all this for you so take advantage of it.
  
• Don't sit on defense buffs. Gladiator in particular gets a lot of them and you can usually use at least one for each group of enemies. The difference is noticeable.
  
• Keep all enemies gathered in front of you if possible. You can only parry/block enemies you are facing and your evasion is higher when the attacker is in front of you, and the occasional damage reduction adds up. There's a good amount of endgame tanks that don't do this and it makes a pretty noticeable difference on how much damage you take just like throwing out buffs.
  
• Some dungeons are just difficulty spikes. Off the top of my head, Brayflox's Longstop and Stone Vigil, both main story dungeons, are a big jump in diffculty when you first enter if you're at the base entry level.

Oappo I'm on Hyperion too so if you have any questions you can feel free to send me a tell.

[Canadane]

Is that one new? I don't remember seeing anything about it in patch notes.

Well it's not new, the armoury bonus has been in since 2.0.
But below level 50 it's +100% exp gain, and between 51-59 it's +50% exp gain.

[Niwashi]

Well it's not new, the armoury bonus has been in since 2.0.
But below level 50 it's +100% exp gain, and between 51-59 it's +50% exp gain.

Ah, I hadn't recognized that as a description of the armoury bonus since there's several things wrong with it.

The "at Level 50" part is wrong. (It starts at level 10, as soon as you're able to add additional classes.)
The "50%" is wrong, at least for "below Level 50". (It's actually 100% before level 50, and 50% after level 50.)
The "from FATEs" part is misleading. (It applies to all mob kill XP, and isn't specific to FATEs.)
And the "may require finishing the first part of ARR's Main Scenario to unlock" is wrong. (At least that part was tentative with the word "may", but the short answer is no, it doesn't require any part of the MSQ, just the class quests to unlock a second battle class.)

A somewhat better description of it:
Whenever you have more than one battle (DoW/DoM) class, any that are not currently your highest level one get an XP bonus on mob kill XP. For classes below level 50, that bonus is 100% of your normal XP. For classes level 50 and up, it's 50% of your normal XP. (And "class" here also includes the new jobs that are both class and job rolled into one. In the gaining of XP, they're acting as a class.)