I believe that there could be some weeks availability at points affiliated resorts, but it really depends on the resort in particular. When a resort is points affiliated, you can convert your weeks to the RCI points system, but that usually isn't mandatory so there could be some weeks-based inventory still. It does mean, however, that if you own a weeks unit at a points affiliated resort you won't be able to use the points for deposit with that week; if you want to use it for points you have to convert it full time to weeks for $$$ rather than the occasional single week conversion.
Re: using Wyndham points for RCI points affiliated resorts, you can going through the Wyndham RCI portal via the external exchanges link. The point cost for a resort that way is different than the point cost in RCI points, which opens up some options for arbitrage if you own Wyndham and have a week enrolled in PIC. There isn't a real exchange rate between Wyndham and RCI points, but instead a unit-type and season chart for how much an exchange will cost you in points.
Hope that helps!