Executioner: Have to let Roche kill Henselt (before that you have to kill Adam and Aryan).
Exorcist: You have to dispel the curse from Henselt.
Swordsman: You have to defend Henselt from the 2 kingslayers.

My question is, can you get more than 1 of those, or concerning Henselt, at Roche 's path, you end up choosing only one out of those 3 outcomes? Can you get both Exorcist and Swordsman, for instance? Or getting one of those, ruins the chance of getting all others?

You should be able to get all three on Roche's path. They are not mutually exclusive.

Yeah you can get all 3.