I don't think you can turn off Temporary files, but you did not say which ones you were referring to.
If you use Disk Cleanup, it says it will remove temporary files, and you may be able to schedule it or set up a Task in Task Scheduler to do that for you.
As far as passwords on a specific folder, the only other user that is supposed to have access to your stuff in an administrator. I suppose you could try setting up the sharing options or security options to deny access to anyone but you....
Knowing what type of users you were trying to keep out might lead to a better answer.