Question by a fledgling scholar

[Foxkid]

Congrats!
Your technique is alright but you might as well use Largesse
What I do while I am playing as SCH is to cast Adloquium before the tank catches aggro (this might attract aggro so stay close to the tank) once the monsters are pulled usually turn on Largesse and heal using Physick and Adloquium.
Unsure about the last question.

I actually tried using Largesse early on, but I didn't see too much difference in it including during Eos' Fae Illumination so I replaced it with Lucid Dreaming which I feel helped out more during heavy healing phases (mp management) and I've adopted in using Adloq before the tank runs off, which helps especially well if the heal manages to be a critical for usually 2k or more (4k shielding).

Tanks should not be pulling trains pre 50. Healers don't have the tools to handle them yet, especially SCH. The 50s dungeons is where the train pulls begin and some players forget or pay no mind to the capabilities of their healers.

In these cases it's important to remember that if you do nothing you will gain no enmity, and as crappy as this sounds, when you see the tank bite off more than he can chew, let him die. Your only alternative is to go down with the ship, because as soon as you do anything, the angry pack will come for you after the tank drops.

This isn't something to spite the tank, or teach him a lesson. It's looking after your own ass.

Well, it wasn't a thing that really happened until I started hitting level 32 with the goblin lair and Stone Vigil at 41 and higher, so I started feeling both annoyed and discomforted when the tank both pulled half a room (or 2 rooms) of adds (annoyed) and then had the entire group wipe shortly after because the damage was higher than my output (discomforted for the dps dying when they didn't need to).

However, would the mobs really straight ignore you if everyone else drops and your aggro is virtually zero (minus Eos and Selene because their aggro is usually higher than mine)? Usually even if I stop doing anything when the tank falls short of swiftcast + resurrect they still come for me once the dps drop in a corridor.