"but your dealing with minute hardware where every single ms of processing power counts. Simple encryption should be utilized [but then this might be easily hacked anyway ?] but for units placed inside the body [pacemakers and the like] - splitting the units resources between keeping the patient alive vs. encryption for wireless protocols seems to weigh more heavily on the former than the later given how unlikely - for the majority of the world - these 'attacks' are going to be."
So your solution is to increase security such that it compromises the functionality of the device itself through it's utility ? High security, poor battery life ? High security, high replacement cost ?
"Point 5 is the only one that I am concerning myself with." - and delivering insulin isn't important ?
Get realistic - security loopholes are only as important as what you are trying to practically protect and at what cost with what risk. This is what I am trying to make evident.
The assumption that every single manufacturer in the medical industry hasn't considered security of remote devices seems a far stretch to me given the prominence of medical litigation and the fact your dealing with someones life. Is a high security cost, high device cost, low battery life and therefore low adoption for patients and community accessibility acceptable? No, it's not.
The world is not based on everyone wanting to kill each other because entropy of serial numbers [which you nor I have any idea about] are low so they can hack insulin devices and kill someone. That said - it needs to be fixed with a balance to risk and all these other factors.