I want everyone to have all the possible rights to all of these things in this directory and everything that is ever created in it in the future.
No, you really, really don't want to do that. You are solving one problem and creating many more.
What you want is for each user/process to be able to read/write/delete their own files but not break other things. Fortunately you are not the first person to come across this issue and there are two perfect solutions:
use /var/tmp as the cache directory, as it does this already
set the sticky bit on your own cache folder: chmod 1777 my/tmp/
gets a bit more complicated if it's a network share, but OS X server has access control lists to help.