Is there supposed to be zero backlash rotational play in an inboard CV joint For example hold the axle shaft and turn housing back forth. There is when I do it?

No, unlike outer CV joints, inboard CV joints have some rotational backlash. This is a clearance that is present to allow for the differences in the rotational speeds between the transmission output and the wheel due to the plunge of the joint as the suspension moves up and down. The amount of backlash should not exceed a few degrees, but it is normal to have some play.