The point I was making is if you use the two diode clamp, you MUST connect VSS to one side of the AC mains. The voltage driving the PIC pin is a clamped version of the AC on one AC line referenced to the other. The consequence is the PIC (whichever type) must have it's VSS pin connected to one of the AC lines and it's 5V VDD supply must therefore also be reference to one side of the AC. In a completely isolated environment that isn't an issue but be careful to observe the safety aspects, especially at the switches which would be 'live' compared to ground.
To completely isolate the PIC and switches you need to use opto-couplers but not wired the way shown in your diagrams. The whole AC side must be isolated from the PIC/user side.
Brian.