Has the missing ball(s) caused any issue with your printing? Have you completed assembly and printed yet?
Have the bearings that fell out of your housings caused you issues? Have you completed your build since?
I also did not push hard on the rods and the bearings were definitely not overtightened, but a few bearings fell out of each of the housings while the rod slid through. It is not terribly rough but still not as smooth of movement as I expected with the plate assembled. It slides, but I wonder if the 3-4 little bearings that fell out of each of the two housings will be a problem now.