1) The shield is kinda unfavorable because most of the time, it leads to a group of aggrivated gamers. Maybe instead of completely blocking basically 99% of all weapons, it could block a percentage of the damage taken. This could help with the initial game play. In the begining of games, some people have not had enough time to scatter. This leads to constant use of ranged weapons. In some cases in higher lv games, this literally ends the game. The shield could prevent the initial use of weapons such as nuke or pyrotechics. The shield can also be used to run away from a jugg with minimal damage taken without causing everyone to get pissed. 2) emp stops people from moving for 3 turns and this can also cause some anger. Instead of completely stopping movement, it could slow down the target from shifting too far.
Instead of saying the issue is that people get triggered, the problem is how the shield greatly unbalances the game currently. In team death matches, a teammate using a shield passes damage to the other teammate. This disrupts tatics in a toxic method. In allshot games, 3 turns allow the player to be literally invinsible. it just kinda breaks teamwork in a way that requires only one person to use it. For the emp, i guess itbis a punishment for people stacking or stopping a juggernaut, but punishment is a pretty long time. In addition, I think invisiblity is better than the shield. It provides the same tatic, which prevents attacks from the enemy, but also allows "EVERY WEAPON" to be used.