The extra waterproof fabric layer sounds like a good idea.
I also know that there is a lotion or wax for wetsuit chafing that might work.
I was also told to never use vaseline or a roll on deodorant when using a wetsuit because it would cause the suit to break down.
The Duct tape sounds like it would work. . . . To take some of the YANK! OUCH! out of duct tape-or any tape--I pull the length I want off the roll and then first lay it on to my pantleg, or wrap it around my middle against my cotton shirt to take some of the sticky out of it.