Here is a few ideas I have been thinking off.
Like a radio mod for the officer in charge of the pump... for example you click on them, it gives you a radio symbol and you click on it, and you can request ambo, police and then make pumps.
so if you select make pumps 3, the mobilize on there own. Then at the same time, if you sort the fire or incident out, you select no further assistance required.
may be really hard to make!
Good thing to see on the map, is maybe a fire and rescue training centre, so they have a few drill towers in a yard and a swimming pool and other bits? you could also keep spare pumps there, or even build it on to the back of a fire station?
just a little one.... before you hear the turnout noise, maybe make a turnout printer noise, and maybe turn out the lights on station when you turn a pump out.
Any more i can think off I will post.
If you need help modding at all, give me a shout!