What is the most important among the proficiencies? My cloak & dagger is 70. Do I need increase the Cloak & Dagger? And what is artificer's slots Difficulty 20 to 10 of snakeskin boots?
Proficiencies are needed to be able to get skills on the one hand, and most of them have some sort of effect/bonus the higher they get on the other. For specifics on that, look here: