Tossing a point or two into your non-main skill trees is fine, though you won't be able to max out more than 2. All trees have useful novice skills.
Willpower is very useful. With independent and a point on gear, it only takes 5 skill points to get 5 willpower, which will save you from all kinds of nasty stuff. You can get walk it off and invest only a point or two in bodybuilding and you'll have pretty good resists overall.
