I think she was getting ready to leave when a car pulled out of her blind spot at the side of the road, which caused her to brake, and then the next vehicle was full of thugs! And we have all seen what happened next.
Yeah, the one that apparently got dragged 100yds down the street 6 months ago. You would have thought he would have learn't his lesson by now, not to stand in front of vehicles, unless of course you want to use it as an excuse to murder someone!
Don't get to hooked up with what you buy now, as long as it will function for the next couple of years, then you are on your way, just pick a decent brand.
I'm not convinced the tiling is the problem, the internal picture of the damp around the skylight, is that the rear of the skylight, near the main house where it has been knocked through?
It all looks poorly done to me. If you are sure it isn't a condensation issue, then get it retiled with appropriate tiles.
Why are you not calling back the original builder?