You're complaining that your mage is wiping the floor with people who are rolling 4 dice? Those were mooks... their job is to die spectacularly.
Also, in regards to Mob Control, et cetera. Its untenable in actual play, I don't think you are running it correct...
First, roll spellcasting vs resist. If successful, note net successes. Nothing has actually happened yet. On their action, instead of doing something, they resist again, whittling away at your successes. Then on your turn, you issue a command. On their turn, they roll again, whittling away again at your Hits. If they don't, then they perform whatever your command was. This is three resistance rolls against your one roll... if your dicepools are -that- much better than the opponent's, then you deserve to instantly win.
Second, the rules do what they say they do. There is no "commit suicide" action. Miscellaneous actions are allowed if I feel they are appropriate. While I will houserule in random stuff that makes the game better--you are not entitled for me to houserule actions into the game. Now, shooting yourself in the head is a an action and something the NPCs can be made to do. This is a called shot. They roll their attack with a -4 penalty (no defense, I'll give them that). It deals the listed damage, and they soak it normally. That is how it works because that is how the rules says shooting anything in the head works. If your players complain it should be instantly lethal, explain that you're the GM and that sticking to a strict reading of the rules makes the game better, and to please go along with it. If they still complain, tell them to read up on Beethovan's relatives, also anatomy books. If they -still- complain, have an as-before-unseen NPC perform a called shot on their head, then politely ask them what should happen. After the results of the fight make sure to build rapport later and have one or two positive interactions before your next game.
Get used to banning incidental power in your game. The faster you learn to do this, the easier things will become. Just make sure you also implement the "Rule of Cool" as well. Lateral thought is allowed as long as it is interesting.