Reckon this was a quick and dirty synopsis and there are many more factors to take into account.. but the main point is that a short action will deflect less due to length and stiffness for a given load imposed in the system.
Well all of that would be a great answer if the tang was actually taking any recoil. It's not. The recoil is transfered through the recoil lug to the stock which is in the front of the receiver. If the stock isn't fit properly and the tang does transfer any recoil to the stock you end up with a split stock right behind the tang.
Basically every part of the receiver and bolt behind the front ring just sits there during firing.
Assuming both the radial stress and the linear occur simultaneously we can deduce that the bolt face is acted upon and barrel channel under chamber first.
Don't assume.
The chamber preessure has to build inside the case before the bullet starts to move. Only after the pressure has signifigantly risen is the bullet released fron the case mouth and begins moving to the lands of the barrel. And then only after the pressure has risen to 60,000 psi +- does the bullet continue down the barrel.
The radial forces in a chamber happen way before the linear forces do. As "way" as you can get in a milisecond.
The action screws do not play any part in the recoil of a gun. They are only there to keep the firearm inside the srock. There is signifigant clearance 360 degrees around them so that they do not contact any part of the stock.
A short action does not necessarily have a faster lock time. The firing pin is smaller and lighter yes but the spring is also smaller and weaker than a spring in a long action firearm. Thus canceling out the lighter firing pin. They both have to be cocked the same distance to get sufficient momentum to dent the primer.