Not sure if I can put this in Bumpersticker form...
1. Maybe "Look ahead".
Which is short for: Pay attention to terrain. See slightly open doors, broken windows, cars parked in the wrong place, an absence of people where there ought to be people and so forth.
Look for the signs of an impending attack. Avoid the trap.
2. Learn to shoot.
Which is short for: Work with your sidearm and ammunition until you know exactly how far it will shoot accurately, and how much hold over you need at that range. Practice the draw until you can do it without thinking, other than the signal to do so. Practice until releasing the retention device, getting a proper grip on the firearm, withdrawing the firearm without getting your finger on the trigger and such without thought.
Because your brain needs to looking and evaluation what is going on. Who needs shooting, who needs shooting first, who needs to NOT be shot. Have they seen me? Can I back out and get backup without sacrificing the victim in all this?
3. Maintain equipment.
Right? Gun is clean and lubed as needed; ammo is fresh; radio battery is charged; underwear is clean. All this needs be attended prior to jumping out of car and charging into action.
Nothing wrong with your list.