Re. water in the door itself: Many newer campers I have seen had small drain holes in the lower edge of the door (the aluminum channel surrounding the door itself, not the door frame).
Older campers do not have this. I know my 2002 Lance did not. Water entered into the door, which is just a piece of styrofoam sandwiched between two thin plastic sheets. There is nothing there to prevent water from getting in between the outer sheet and the door surrounding. Once inside the door, it will find the easiest way out...
You can easily drill holes into the underside of the surrounding aluminum channel of the door yourself. Doesn't cost anything and gives you some peace of mind ;-)
BTW, this was my resto story:
http://www.walzenbach.de/MK/BogQueenEN.htm