Yeah i didn't cause wipes or anything, also kill speed isn't really me
Kill speed isn't really the tank, but pull speed is. Generally every dungeon past ARR leveling is designed to be pulled several packs at a time, quite often "wall to wall", which is basically sprint and aggro everything you can until you can't progress anymore(door closed, rocks, whatever, that'll disapear once you cleared trash). A few or the earlier ones don't have these limits but later on that's how it works, and every dungeon is super linear so as long as you look at your map for directions rather than visually trying to find the way(which can be super confusing at times) you can run pretty quick even the first time. And generally you'll want to group 2-3 packs together for aoeing so it goes faster.
Mind you if your gear is shit, pulling several groups is a good way to die. Armor is actually fairly relevant for tanks, unlike DPS who can get by using outdated garbage as long as they keep their weapons relatively fresh. I'd say upgrade your armor and weapon every ~10levels before 50. After 50, you just want to buy Ironworks at 50 and Shire at 60, and just upgrade whatever you find in MSQ dungeons but not bother much more. You'll have to be careful if you haven't upgraded your armor(although the MSQ gives a bunch of HQ gear for that) in the 57/59 and 65/67/69 dungeons(65 because Bardam mobs are notoriously vicious, even with the right gear). Still pulling packs 2 by 2 should be np, just rotate these cooldowns and keep an eye on the healer to adjust, if they're not DPSing and casting a lot of heals but overhealing, you can pull more, if they're not DPSing and casting a lot of heals but not overhealing(you're taking a lot of damage), keep that pace or slow down, if they're DPSing almost the entire time, you can probably pull more.
Side note, just did the free transfer and made a bunch of money just for transferring. Bought a house plot before moving and apparently they reimbursed me the plot price on the base price rather than the reduced one? So like ~3m instead of the 1.5m I paid(Goblet shitty plot at min price), plus another 3m for "furniture" even though I owned it for like 10secs. And then 1m for my appartment(500k for the price I paid and another 500k for inexistent furniture). Should make a little bit from some Rakshasa pieces I bought before moving too.