on Character Advancement:
"When advancing your character, you can take profession talents from outside of your profession, though you must always find a trainer to help you for the first rank.".
I think that taking talents from outside of the profession should not be, instead you should have a companion with the complementary talents you need, so, if the companion dies you lose his talents.
E.g. if your character is a Hunter and you want to be able to cast spells, create a companion sorcerer, and I don't know, the mishaps are shared , and if he dies, you lose the talents of your companion sorcerer.
The companions can be made so that they don't gain willpower points on their own, but can be transferred to the main character as if it were a forced roll together.