Ok, I am slightly confused so someone can probably enlighten me and help me out:

Here is what I know:
If you attack the other faction inside a quest hub with faction npcs they will attack you.
Now, there are certain scenarios I am not sure of:

If the other players faction with the npcs is lower then yours, will the NPCs still attack? Does your faction standing with said faction influence if they attack your opponent at all?

How come classes can send in their pets attacking players with the guards not doing anything yet if you fight back they attack? Is that linked to the faction standing of the player attacking? Meaning he/she has much higher faction then you do?

Is it an exploit that I get dotted inside a faction area yet the npcs don't attack (or is the range for some Pyromancer dots that long so they can cast it from outside without being in range of the npcs?)

Thanks in advance!