Last modified: 2006-06-03 03:04:40 UTC
Keep the "edit" button for protected pages. Add a little icon in that tab if needed, to denote the protected nature. Offer a message on editing, varying by protection type, explaining briefly why the protection, and where to post edits and suggestions (the talk page), with a link to a longer explanation of who can edit where, how to request unprotection, how to ask for help, &c.
* Extra 'protected' message in tab
*- Potential extra icon
* Extra Wikimedia message on editing
NB: If you want to show users a "show source" tab, it should always be there in every interface, whether or not the user can edit the page; anything else is confusing.
The 'edit' button should not say 'view source' -- the interface should clarify that one is seeing the source for cut-and-paste -- and not for editing -- only when the user views the edit page, in the context of its clarification about protection policy and implications.