I am leveling an Arcanist as my first character and looking to add 4-8 levels of Conjuror to supplement my current abilities (Stone has a stronger potency than Ruin, Aero would combine well with Bio to wither opponents away, and Protect looks like a great thing to have in general.)

My question is, if I get to level 8 of Conjuror then switch back and continue leveling Arcanist (currently 16), would my use of Aero and Stone be treated as level 8 skills since their origin class is only level 8, or would they be treated as level 16 skills since Arcanist would be my active class?

Or do abilities even scale with class level at all?