When the rifle is shooting right of aim, the barrel/front sight is canted to the left of index of the upper receiver. The easy fix is to just remove the barrel from the upper and re-install the barrel at the correct index to the upper.
The M-4 butt stock has a locking ring that is used to tighten the buffer tube to the receiver. There is no end screw used in the assembly. It goes tube, nut, then plate to retain the rear take down spring. once you have indexed the butt stock with the lower, then use the car wrench and tighten the retaining screw. It helps to have a lower mag block to hold the lower. With out the block, it takes four hands to install. Two to hold the lower, one to hold the butt stock to index with the receiver, and a forth to tighten the retaining nut.
As for a post-ban style, I am at a lose. Never felt compelled to build a mock car, just figured if the stock stayed extended, may as well be useful and have a cheek rest.
If you don't have the tools, then either you will need to send the kit back for adjustments, or just buy the tools needed to build the rifle correctly. If your smart, just buy the $50 in tools needed. You will use them countless times repairing your rifle and come in handy if you decide to do a yearly teardown and rebuilt.
Note: Complete tear downs of your AR collection is best done when there is a two day blizzard outside, you have finished all your winter projects, and the Wife has informed you that are standing knee deep on her last nerve!!!!!!!!
P.S. The one item that most people miss when they price a kit is the needed tools to build the rifle. Granted that you can buy a built upper, and built lower and combine the two, but even on this, you are still the smith. The function check and tuning are left to the you; the builder.