I will address two very small topics you brought up as a way to educate since you evidently do not understand the rational.
1) The AR and CR signals on a throw-in, goal kick and corner kick are not as cut and dry as you think. The referees work as a team with the CR being the boss. The one thing a referee team does not want to do on a throw-in is to have the CR pointing north and the AR pointing south. That diminishes the referee teams credibility and confuses the coaches, players and spectators. So when a ball goes out of play over the touch line, the AR should shift the flag to the hand that he thinks the direction of the throw should go and make eye contact with the CR. The CR will observe which hand the AR has the flag, make eye contact and if he agrees signal. Some CR will move their hand out about 6-10 inches from their waist in the direction they think which is a cue to the AR as to which direction the CR thinks the throw should go. If the CR and AR agree than they will both signal in the same direction. If they do not agree, there are little signals the CR and AR can give each other as to what they saw or, as I prefer if I am close enough, just ask "what did you see" or I will say what I saw. In the end, the CR and AR should always signal in the same direction. So, that is why AR's wait to signal. Same basically goes for GK and CK.
2) Something similar happens when the AR sees a foul. The AR makes eye contact with the CR to see if the CR had seen the foul. Then the AR runs through a few internal questions depending on what they saw, "Would the CR call it if he had seen it?", "Is there an advantage possibility the CR is letting play out?", "Is the CR taking a "wait and see" approach to this foul?", "Does the game need the foul called?". All of these questions and possibly some others roll through the AR's head in well less than a second while making eye contact with the CR. Then the CR may give the AR a very slight hand signal that he does not want the foul called. These signals are not standard and a good ref crew will brief them prior to the game. I had a foul occur right in front of me (AR) yesterday that as a CR I would have called, but when I looked at the CR he gave me a slight hand gesture "no" that he did not want it called so I did not call it. Had I raised the flag to call the foul, the CR would have just waved me down and caused players, coaches and spectators to yell at the referee. As a rule of thumb, ARs should not be calling more than 1-2 fouls per half in a 90 minute game. If the AR is making too many calls than there is a problem within the referee crew.
So, hopefully now you have a little better understanding of the CR-AR relationship and that it is not as black and white as it may appear.