Thanks all. I knew when pondering getting them that it was sort of a catch 22. Not having ever had them I am going to give it a bit and at least see how bad it gets (the razor knife was DWs idea after I told her I would not take it out in the wind
).
My biggest concern is the topper damaging something else. I've lived in windy country all my life and I've seen all manner of things torn off, torn up, blown away etc. - including an entire sheet metal building blowing over my fence into my property...from just normal wind here. It can get pretty stout and it's not uncommon to have 50, 60 or 70mph winds.
The conversation was precipitated by a talk I had with another owner that said when the winds really got up he had to pull in his slides; that is a no go for us if we are staying in it. I will try strapping them down in some manner to see if that works. My intention ((hopefully) is to be in places the vast majority of the time where the wind concern is unimportant.
As far as the water I guess I'll just let it build up then come off when the slide comes in. When I had it out here in the rain it was a literal waterfall coming down the sides as I pulled in the slides. I would think that much water would stretch the fabric and just compound other issues...just don't know yet. Thought about the trick of putting a ball of some kind under the topper but don't see how that is going to keep it from pooling unless I put a 1/2 dozen of them on each of the slides, plus, I wanted them so I didn't "have" to get to the tops of the slides every time I went out.
I'll give it some time and see how bad it gets. One of the big positives about getting them, in my mind, was the ability to park again under trees. When I had trailers with no slides I parked anywhere/everywhere. After a couple of times doing that with slides and having to clean them I started scouting places and made sure to park in full sun....that is not fun in the summer. I was hoping to "get in the shade" again. Thanks again for the thoughts, hints and guidance.