I'd like to restrict access to certain forms to admin users only. Is that possible to do at the form level? 

Is it possible to create read-only records? i.e. Once the record has been created, it is not possible to edit it.

I am working in a sandbox right now, and the user permissions do not show in the Settings section. Is that expected? In any case it doesn't appear from the documentation that form-level permissions are an option. But I've also found the documentation to be incomplete and/or out of date.