Homebrew PCBs

My experience with the white pulsar paper is different - it dries out
over time, which also causes the curling.  I hold it over hot water
until it absorbs enough moisture to "flatten out" before printing on it.
This is based on some notes that came with the paper from Pulsar, in
that the fibers in too-dry paper won't lay flat when you print, and they
mess up the toner application.

Also, based on recent experience with transparencies, I'm guessing that
any fibers "sticking up" will cause the paper to hold onto the toner
better than the PCB does, which may also keep it from transferring
cleanly.

For the "wave action" - IMHO you need the etchant to be *moving* for a
consistent etch.  You can either do this with a pump or aerator, or just
wiggle the pcb around while it's etching.  For single sided boards, I
just tape the pcb to a stick so I can "stir" it in the etchant.