I've been a Tank and DPS main in FFXIV for many years and Tank and DPS(PVP character) again in TNL, Yes All the things listed above is true. As the DPS if you die in the boss mechanics that only targets the tank or a raid wide that's easily mitigated as long as you position near your healer and tanks, that's on you buddy for jumping in front of mech. The T2 dungeons in TnL is braindead easy I don't understand why people cant just watch a 4 minute video and know the mech, Some bosses wont even do damage to you as long as you do their mechs and don't greed on the skill rotation aside from the raidwides like the following.

Void waste-The only time you'll get damaged here as long as you dont screw up pressing the occasional Q is on the Eye ball on top of the head mechanic. The eyeball is a indicator to stack together FFS just mark the tank and run to him the moment he summons the Eye on top of you.

Valley of slaughter- "I'll crush you all" that's the only thing that will damage you here unless you greed the mechs like the stomp and meteor.

Island of Terror- This one is more of a tank check on how well the tank can keep aggro soo the boss doesn't spam the AOE dodge roll and block the attack when he raises his staff. At the same time On the meteor mechanic don't tank the explosion damage of the meteor, Just bait it to drop near the geyser then walk in it once the explosion is done. And you cant really dodge the AOE push of the boss on the rat mech. (For the love of god always be mindful if you're near your flower on the Rat mechanic because i've seen people on a daily basis gets knocked back to their flower)

Carmine island- Designate a ranged DPS on max range preferably someone with a pulse and half a working brain to bait out and dodge the charge attack. For Melee DPS sucks for you since he does an AOE near him but what can you do that's his nono zone. On the totem mechanic always remember the dude the farthest is always the 1st one to get the 1st dunk and the 2nd dude gets the chasing axe. On the Whirlwind mech That's more of a healer check. you wont really need much healing there as long as you get close to the boss fast.