These are mechanics I can get behind. Only a ~33% chance of failure? I like those odds. Especially if my ludicrously broad trait "Jack of all Trades" is rank 10! Haha, no, no I would never do that. Or would I? Easily countered by an NPC's "Murphy of Murphy's Laws" having a 10 as well. Why do you think Murphy is so intimately familiar with those Laws?
One has to wonder what a temporal consequence would entail. Are we talking ridiculous Dr Who temporal phantoms which are easily defeated by a church, some sonic waves, and an impossible (not improbable, mind you) interruption of the temporal loop, or are we talking becoming your own mother AND father type horror stuff? Whatever it is, it's bad. But it's oh so good!