re: My solution to veneering a large panel.

For clamping veneer, it would probably be a good idea to put some plywood between the cauls and veneer to spread out the force a little and reduce the chance of issues from localized pressure.  I would wax the plywood or even put some sort of plastic sheeting between the PW and veneer just in case there is a break or something in the veneer that allows glue to seep through.  Gluing the plywood to your veneer would be a very bad day.