AccessDeniedBitch
First off, your point is a valid one worthy of attention and discussion. The responses that the other guys gave before me seem to completely miss your point and not actually address the issue you brought up (except 1 or 2, partially).
I think you are dealing with a misunderstanding. While i am NOT 100% sure that what I'm about to explain is true, I think its likely the case, and maybe it will be of help (since no one else is giving an authoritative clear answer).
As you know the BT hardware is baked in one chip with the wifi. So its impossible to physically isolate or remove. So then we need to look at software.
I think the reason the system BT app has these permissions is because it HAS TO have them in order to be able to even affect the hardware. For example the "settings" app has access to all kind of things too. If you were to remove those permissions then the settings app itself wouldn't be able to turn them off or on, and you are left with no ability to even affect those settings. Now that wouldn't be practical now would it?
Likewise the BT settings app is I THINK the deepest app that actually controls the radio systems. If it were to lose permission to touch that hardware then you'd be in a quagmire. I think the BT settings app is the most fundamental app that actually controls the hardware settings as well as whether other apps get access to the bluetooth input/output data. So it is like a driver i think essentially.
I could be wrong but i think essentially those permission are not actually real permissions and cant actually be removed, and the fact that they shown as permission may be esthetic only just to show what its affecting.
I'm pretty sure what i have explained is not totally correct but i think its in the ballpark.
Now the reason it shows access to things such as sensors, images, contacts, etc, i think is because the bluetooth stack (if it were to be used) needs access to these things because these are the things (data types) that people actually want to access to send through bluetooth. So then the secure way to do it is to compartmentalize each category of data and put security access switches in front of them (as has been done in android) and present the whole thing as a ladder of multiple levels of on/off switches that affect whether the rest of the system can gain access or data can be passed to them.
So the reason it shows access to x, y, z, is because it needs to be able to access those elements WHEN THE USER WANTS TO, and gives permission. But these access points are each gated by the permission system which the user has control over.
Its like, the coat check person HAS TO HAVE access to your coat in order to fetch it for you. Imagine if your coat was back there and the coat check guy couldn't actually get it even if you wanted because he doesn't have permission to physically touch your coat.
And lastly, since people MIGHT want to use bluetooth then the only way to do it is to make all systems working and available, but switchable for the people who don't want them.
So in fact i think the bluetooth switch actually does what you want.
Now if you happen to have any external links that show or talk about this bluetooth hack that you mentioned it would be nice if you could post so we can read about it as well. Or was this a personal event that happened to your office?