@BSod
You are right, the bmw boxer motorcycles are widly-used by cops all around the world. Even though they usally used another model that has a fairing. Now the old "airheads" have been replaced by the newer generations, but the old machines are still quite popular. They are just really reliable, sturdy and can take a beating.
@burning_phoneix
Yeah motorcycles are more dangerous than driving around in a car. That's undeniable, but the experience is also very different. I know of the risks, I accept them and try to minimise them, but you know shit happens and I bet that every motorcyclist can tell you a couple of stories.
@Crimson
A lot of problems with bad idling happen due to the fouling of the intake system as the crankcase ventilation is connected to the intake. This is mostly done to reduce the emissions, but the problem here is that oil and other particles can reach the intake even with the existance of a seperator.
So after a couple of years the throttle valve will look like this:
The throttle valve is the disk in the middle that turns when you press the gas. Thus increasing the area and air flow, which results in higher rpms.
The picture shows my parents' car, which had problems with the idle. After cleaning the valve and the intake with a brush and fuel the engine was running properly again. The thing is, that we have been to a garage before, but the guys are not really interested in this kind of work, they can't sell you new parts and it doesn't really take long. They are just not interested in cleaning stuff…
Another possibility for the problem is the air filter of the engine, if they don't get exchanged after a while. The filter element can be clogged, so that the engine doesn't receive enough fresh air.
Well exchanging the air filter is usally possible without special tools and experience. Cleaning the intake and throttle valve is a bit harder. You have to dismount a couple of things and sometimes the valve isn't easily reachable and so on. Also I am not familiar with your model and it's also possible that the idle air bypass valve isn't working properly. It's always hard to tell stuff from afar…
It's actually not that hard and if you do want to try it, you can watch a couple of videos about the matter for instance this one
If you never start working or thinking about engines, you will never be able to understand them. I know that it's more a "guys thing" to do, working on engines and stuff, but there is nothing mysterious about it.