1. Well here there is very few high rises. I could probably count the number of buildings over 10+ stories on one hand. Now I can see where your coming from, and in this case I agree having FD on hand is a good thing, but this seems to me like a case where FD could be dispatched on a need be basis. If the call comes from a high rise structure, then FD is dispatched along with EMS.
2. Not enough for a call or not enough to for a second ambulance to provide support?
3. Nothing left to argue 
4.True the truck will break down but then again most of the trucks we have are from the late 80s or early 90s. Only 3 trucks, not counting 1 Rescue, Hazmat, and Brush truck, and only the Rescue truck sees front line action on a daily basis.
1. true, the dutch is relative flat. only a few city have some "high" rize buildings, and those aren't above 50 floors.
2. No ambulances are placed by district, sometime you have 3 ambulances on 4 "citties" (for instance, the Bergen op zoom EMS service, they have 3 ambulances, and have to guard, Hoogerheide, Woensdrecht, Huybergen, Ossendrecht, An off course Bergen op zoom + the highway between them and a province called "Zeeland". So some times there just aren't enough EMS services avalibol, and they need help from another dispatch area(in this case it would be "Roosendaal" (witch has 6ambulances (but the same kmĀ² to guard)
3.
4. Well you can talk about this until the sun goes down, fact is, trucks will brake down, and new equipment is brought out, i think the province/state/county/nation has some sort of line set on when the trucks needed to be replaced/updated/fixed.(same with all other EM units).