Bindings can absolutely be too stiff for a board. Personally, I'd rather err on the side of a little too soft rather than too stiff when it comes to bindings. Then again, I prefer stiff boots, so I think that plays into things for me. Pair stiff boots and bindings on a board like an Evo and that thing gets mighty twitchy. I don't think the Contact Pros would be stiff enough to cause an issue though.
"People say that marijuana smoking is going to get in the way of my career. I say to them that on the contrary, my fighting career is getting in the way of my marijuana smoking." -Nick Diaz