Is it a bad idea to run a back haul and an AP on the same router board?The wireless card for back haul is a XR5, the AP is R52H, and Rb532a. Some people believe its better to have two separate dedicated devices. Any suggestions?

Its fine (less downtime also)

just keep much channel space between them.

I only use a backhaul only board for multiple backhauls running through a site. If it is only a backhaul to a site and then sectors or an omni, then it is ok to use same RB532.