Shower Skylight Leaking - Quick repair or "go for it"?

To the OP of this topic. I'd consider tearing into the ceiling around the sky light and at the very least see how far the damage has traveled, you may be ok just drying it all out well and mold treating the wood, then replacing a small section of ceiling. Spent last winter fixing the interior of a 2006 Gulf Breeze that i had changed the whole roof including substrait in the fall. It was a good winter project. You will be able to see a lot from the inside and decide if more exploration is needed.