This is absolute nonsense. I join VTs with my ultra plebby alts that barely have 1.5k and can't hold 350k dps to save their lives. Mechanics are abysmally basic nowadays:
On the sumo guys, two people tank them, everyone else insta grinds down the dummies that spawn, then kill the minibosses;
Next you have the floaty balrok thingies from the glacial basin - dps it down till it's dead;
Next you have Asura. You pick your strongest melee and ranged and appoint them to tank the bosses. Rest of the party just dps and block orbs so the bosses don't enrage;
Next you have the warlock dude - dps down until dead. Kill thralls if you feel like it, not necessary. Assume your assassins/summoners/forcemasters/BMs have enough brain to use their projectile defense skills and stick around them;
Next you have the miniboss with the soldies and lines. Have everyone who has a push/pull skills spec said skills and once the miniboss activates adds, people push or pull them in direction of the boss in order to sever the yellow lines to the soldiers. Cut red lines bybefore you dps into the next phase by going away from boss. Rinse and repeat till it's dead;
Next you have the thrall. This is arguably the easiest boss to deal with - everybody attacks it. Dps until CC bars open. When they open everybody KDs. Three of the players will have a running debuff on them. Those go to the soulspace by looking at the boss after the knockdown. Rest of the party looks away (going to soulspace without the debuff is pointless) at this time. Next cc window opening = stun. If you fail to CC, the boss will do a punishment - if he lifts one hand - it's small circle then big circle. If it's both hands, it's big circle then small circle. If you get hit by it, you get a stack. This is what kills most people here, so look at the hands. You keep alternating CCs with those who have the debuf going in on every knockdown. Do this until boss dies;
Next you have the two giants - stack them on top of each other and dps them down like usual mobs;
Next you get the three acrimors. Basically, get three people to tank them. Dps them down until they die. If you don't have the damage and one jumps to mid, party iframe the explosion it does. They do use flamethrowers and lava puddles in their rotations - avoid standing in either of those as the damage can break your back, even with top tier gear;
Next you have the harpy - do NOT casually waltz around. Coordinate to attack her all at once and dps her down as fast as possible. If you fail to do so, have someone stand 41m away from boss and kill a thrall thingie to zap you out of daze. Dps her down to 0. Doesn't matter who dies at this point;
Next you have the hive queen - tank pulls her towards 10 o'clock. The three strongest ranged dps man the middle circle. Discplaimer - most archers do NOT play the ranged spec.
The only two things you need to know about her basic rotation - when she lifts herself into the air, you need to use a longer iframe, as she'll use two knockbacks one after the other. After those she'll do two swipes towards the tank and then she'll grab him, opening her CC bars. You need to stun or daze her. Doesn't matter which, as long as it's not a knockdown (as not every player is familiar with how she will move depending on what she says upon getting knocked down). The party should have enough IQ in between everybody to coordinare stuns/dazes;
At specific points, she'll go back to mid, stopping the death zone from moving clockwise (don't step into that one. It hurts to the dark realm and back). Then three big spiders will spawn, followed by three groups of small spiders. AoE the small spiders and move next to big spider. Now grind the small spiders down until their red aoes activate. That's it with the spider mech. If you successfully pulled all small spiders and dpsed them down so all the aoes touch the big spider, the big spider will die. While this is happening the queen will keep throwing stingers around. Usually those need to be baited, but you can just face tank them. Jump over any blue concentric circle aoe you see, as those grant you the awesome gift of... more stacks, which will be very painful if you get a lot of them;
After the spider phase is done, tank baits boss to 10 o'clock and you repeat the whole thing until she's defeated. If someone died, you can start ressing them once tank baits the boss. This is all for the "simplified" mechanics in VT.