Number 9 asks without applying downward force to the fore end would the reaction from the fired bullet be enough to alter the point of impact or could this be corrected in scope adjustment prior to the shot.
Any change to the resistance amount and direction to the rifle's recoil will change bullet impact from the aiming point. What this does is determine how much and in what direction the muzzle axis moves from where it was when the firing pin fired the shot to where it is when the bullet leaves. Rifles move backwards, sideways and usually up in recoil while the bullet's goind down the barrel.
If you get a zero at each range for each of several shooting positions and holding techniques, then all you need to do is look up the zero for each way you'll shoot, put it on the sight then shoot.
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master