The cops with fire extinguishers will be useful!
In real life, they do have them if I'm not mistaken. Usually, the police are the fastest to respond to a car accident or a minor call that may involve something catching fire. So at least while LAPD is waiting for EMS and FD to arrive, they can prevent the collided cars from exploding
Hoppah, I have an idea for a v1.5 mission: Something similar to the famous North Hollywood Shootout, where LAPD have to respond to a bank robbery-turned-hostage situation.
PD with extinguishers will be a nice addition. An incident that stands out in my mind is from a few years back where a driver noticed smoke and coming from the engine compartment of his vehicle and decided to pull into the gas station as opposed to parking across the street in what was then a wide open dirt field. The Huntington beach PD were first on scene, even though this was next door to the CHP Westminster office, and expended 3 extinguishers before Orange County Fire Authority's Truck 64 (a 75 ft non tiller rear mount quint) arrived on scene. You can see a couple of pics of it here. I mostly took video that day which i still need to upload.
Also in response to the Los Angeles Air Force Base, you are quite right in saying that F-15's do not fly out of there. In fact, nothing does! Unlike most air force bases, this one does not include any aircraft but is the west coast home of the Space and Missile center. In addition to their role in developing ICBM's and other military missiles, they have accomplished many achievements in peaceful meterology and navigational systems.
You're right in saying that the nearest location to find an F15 would be Edwards AFB. Named after Test Pilot Glenn Edwards, Edwards is home to the USAF's Flight Test Center and is also the west coast landing site of the Space Shuttle. While not having a Fighter Wing permanently assigned, you can find virtually any and every aircraft in the US arsenal there at one time or another.
But in game it'd add a great element and can't wait to see it!
Mike