My wife's 2007 Expy sunroof has problems especially when it's winter. Found that the rear sunroof drain hoses run into the rockers (just behind the back doors). The rockers are pretty much completely rotted out, enabling you to clearly see the problem: sunroof drain hoses run all the way to the bottom of the rockers and any dirt/buildup coupled with freezing temperatures plug the tubes. If you have massive holes in your rockers like mine, you can pull the tube forward and snip the end at an angle so it no longer runs into the bottom of the rocker. Pic is looking through the hole in the rusty rocker back at the drain tube (after cleaning out much of the drit in the rocker and snipping the drain tube end off). Front ones run into boxed body member and aren't accesible. Running string trimmer line down them helps as does pouring warm water to flush them out.
Once they plug, if it rains, then she gets lots of water on the inside. Problems described in the original post sound more like kinked or disconnected sunroof drain lines. Good luck!