I'll start by saying that I disagree on all points, but I commend you for starting an excellent topic.
The ball bonus for team color used to be a big issue. When Rayquaza was the raid boss, I was constantly frustrated by getting just 6 or 7 balls to try and catch with, but the Best Friend bonus now adds 4 balls to that. This is more than one gets for team color.
10 and 11 balls is plenty. What's more, this ball bonus means that players are less adamant about getting the gym color bonus. As such, at least in our local meta, the chances of the gym being any color are about equal. When raiding in a group, I'll go from a raid where I get just 11 balls to another where I get 15.
The trading is also not an issue. One needs to simply adjust to the aspects of the game by changing their play style. Never trade an 87% mon. Always trade a bad IV mon for a bad IV mon, if the trade results in two bad IV mons, you have lost nothing.
The shiny premium goes away when you are best friends and already both have the shiny. 800 dust is nothing, and I only trade for IV rerolls on shinies with besties under these circumstances.