PIC Write-Protect Behavior
This is clearly answered in the datasheet.  The protection bits can be cleared, but only by a bulk erase.  So yes, you can reprogram the part, but you can never read out code-protected data.  It may be possible to read write-protected data (that is not code-protected), but in either case all the protection bits are cleared by a bulk erase.  After a bulk erase, the chip is back to factory-fresh state.