This comes with the standard "It's your plane, so do what you want" disclaimer, but if it were me, I'd ditch the second start switch. It adds complexity and the potential for a passenger to hit it by accident.
It also seems like a long shot that it would ever be used and in that 1 in 1,000,000 scenario where a co-pilot is trying to restart the airplane and the prop isn't already windmilling, they can easily reach across the relatively small cockpit to hit the one on the left side.
Heck, I had a student fuel starve me in a piper once by running a tank almost dry (Checklist has you select the fullest tank for takeoff. He switched FROM the fullest tank to one that only had about 5 gal in it and I couldn't see the selector from the co-pilot seat, d'oh!) and I was able to launch across and get to the fuel selector hidden on the sidewall behind his left knee in about 1 second flat. You'd be surprised how agile you get when the big fan starts to sputter
+1 to putting a PTT on the panel, rather than on teh co-pilot stick unless you plan to have somebody hand flying from that side a lot. It's nice to have somebody run the radios without them having to be on the stick, especially with something that has light stick forces.