I think only Simple Finder limits what folders user can see and i think Simple Finder is too limited for our use.
We just want some app which prevents user seeing some folders like entire external drive etc and i dont want to use "make it invisible by adding . to front of name".
You could try putting the desired folder in an encrypted disk image and make sure the password does not get into the keychain. People would see it, but be unable to browse it without the pw.
Get info on each folder when you're in your user account (admin) and select Read Only for Group and Others. Your other accounts on the computer should be less than admin and probably have some finder limitation so apps and dock cannot be changed.