Certainly over longer distances and highway driving, driving faster will get you somewhere faster. In city driving though, where most people drive, it is correct that speeding up for certain portions of the journey will not get you there faster since the increased speed over short spurts can't make up for congestion, stop lights, etc.
Pretty much. Every EVIP (emergency vehicle incident prevention) course preaches this. The advantage to lights and sirens and opticom (the traffic light changing technology) is minimizing stop and go, and optimizing flow of traffic in your direction. They demonstrate that an extra 20mph on your average response, which is likely less than 3 miles (if not quite a bit less), and not much more than 5 until you start to get more rural, is likely only to save you seconds - and there's very very few things where an ambulance arriving literally seconds faster makes a difference in patient outcomes.
But it does slow your reaction time, and it does massively increase your accident risk. And that's couched in, "And now it's going to take many many more minutes for another unit to get to your patient than the few seconds you'd have saved".
