Comically enough, unless you specifically pick up other Skill Bonus feats and equip big item bonus gear, if you get the helm I mentioned, you'll actually have better bonuses for skills that you are not trained in compared to skills that you *are* trained in.
Of course, untrained skill checks do not allow you to anything that a trained character could except with a lower chance of success (theoretically, at least; I've already shown how you can have a better bonus untrained than you can while trained by stacking the right stuff). Knowledge checks specifically state that "A Dungeon Master might decide that certain information is available only to creatures that have training in the appropriate knowledge skill.", and you can only use Acrobatics to reduce falling damage if you are trained in it. As such, I'd probably take those 5 skills as your trained skills and just never take training in any others, which basically equates to being trained in *everything* in all practical ways.