Looking at that frame, no way. the frame butts right up against the wheel with the 650s on. My question would be why would you want to? Yeah its nice to be able to swap wheels, but I curently have 4 bikes all with a different wheel size and its not really that big a deal, just make sure the tool kit has the right tube in it when you go for a ride. I made that mistake on one of only two flats this year.
Not a stupid question at all. Long ago Softride used to have something to allow the old Power-V to be converted from 700C to 650C. Some sort of drop-out insert (some sort of fork change/mods were required, too). But you can’t convert that PowerWing from 650C to 700C.