Using way heavier strings will have a physical effect on the guitar, which guys like LATS or Aschleman are better qualified to go into detail on. It'll mean more load on the neck so you'll probably need to adjust your truss rod if you haven't.

In terms of playing, the wider strings could get caught in the slots in the nut (unless you've already widened them) and I can't imagine you being able to do much but grind power chords... I couldn't anyway - I use 9s or 10s on my guitars.... I couldn't play fast on that much wire.... but then that's me... I'd cut my fingers to ribbons...