My thought would be that scheduling a match every week by hand would be like a less organized flex league (though with a bit of added flexiblity as you can move people up or down within the season). I don't think thats really what I am going for here. If I was going to do that my ideal would be where people could set their availability for hte week and the computer would schedule a match for them against a comparable opponent. But the problem I keep coming around to with this is that I don't know that I could get people in the habit of updating their availability all the time. Maybe this is something that I could grow towards since this would be particularly nice for scheduling doubles.
On splitting by USTA level that is a tricky one because it limits the playing opportunities for players who end up at the top of their level. Ideally they should be able to play against people at the bottom of the next level but that gets completely away from the point of separating the levels out.
I do think that women are more likely to be on board with the system where you don't move down with a loss and the only way you move down is by getting passed up. It wouldn't seem as "hostile" to be challenged if you basically would barely move down if you lost.