I like the format now...but I know it has problems. One thing is not to let those who did not do their fic last time join the next one. I don't know what would fix this and still let new writers in.

I think having several emergency writers is a great idea...I myself have done this at least once and really don't mind it at all.

Maybe recruit some more helpers for yourself and whoever runs the swap too? I know it must be tons of work!