Duct tape is a great idea. I would use it over the booties, because it seems to me that booties would slow you down (creates drag). Careful getting out of the water, though, I can see where it can be slippery.
If you're thinking of doing this, try it a couple of times before the race. Remember: Never do anything new on race day.
Sounds like you had a really good swim, and your time is pretty good. If you want to avoid the elbows and feet, stay to the outside of the group.
"God gave you your body as a gift, so you should take care of it." - My Mom