Need Mercedes ball joint expert advice

[costanza]

Is there a factory spec of how much force a ball joint must be held into the front lower control arm of a '91 190E? If no spec, how does the factory say that the fitting is correct/sufficient?
Other than when a front wheel is completely off the ground and hanging free, is there ever any force pressing down on the ball joint, trying to push it out of the control arm?
It seems to me that the ball joint is almost always being pulled up into the recess in the control arm by the tension of the coil spring pressing down on the lower control arm. True?
If there was ever that much force trying to push the ball joint down and out of the arm, wouldn't it be held in with more than just compression of the ball joint housing against the walls of the "eye" ii fits into? Like with a bolt or something?