Oh lord. Okay, so this is obviously bait but might as well use it to address the points anyway in case, god forbid, someone new sees this and actually takes it as gospel.

1) Wall-pulling vs Fast-pulling is absolutely not a thing. Wall-pulling is your ideal, this "fast-pulling" you're suggesting where you whittle a pack down then move when it's half dead to the next pack is awful. Many jobs have damage skills they leave on the ground that they want to gain full value from, so no matter how much you're pulling you need to pull it quickly and commit to it. Two packs is pretty much the ideal minimum, you can decide to ramp it up from there if things feel good and the dungeon allows it. Should you have to pull single packs, pull the single pack and then sit there.

2) The tank you're playing does not matter that much. GNB's AOE is the same as anyone else's, and your survivability order is nonsensical. Every tank is more than capable of surviving large pulls, but PLD is the squishiest and WAR is the bulkiest. The only major differences are how much AOE DPS you put out, and both PLD and DRK come out ahead of GNB on that front.

3) Invuln use is not that weird for GNB compared to the other tanks. It's pretty simple - Hallowed Ground you use on cooldown (preferably 4 GCDs in if you have a White Mage), the other 3 you just want to give your healer a warning about as you're running between pulls. Try and use them whenever you can, though, since they're incredibly strong. For Superbolide in particular by communicating with your healer when you'll use it you can pop it as you drop very low so the HP loss doesn't even matter, then they have 10 seconds to get you back up for free.

4) Chain pulling smaller groups (this mythical "fast pulling") is objectively not as fast as larger groups. You're just flatly doing more damage on larger groups, and your abilities get more and more value with each additional enemy. The only exception to this rule is if someone in your party isn't pulling their weight - slow DPS, undergeared/not so great tank or healer, etc. - and you wipe, but even then one wipe if you full pull the whole dungeon is still faster than single pulling and never wiping.