Further to my last post on the matter, things have changed somewhat. I am finding that the current sensor actually reads higher than it does when measured against a finger prick test. Its starting to seem like even from sensor to sensor, and location to location, the accuracy is compromised. I was particularly naughty a few days ago, and when I measured with the Sensor + phone app, it was reading 15.1. Because I was relying on the app and sensor almost completely, I dosed accordingly. Then, I remembered that when you get off the wall readings, you should check blood. Blood test was 10.2. So then I checked with the /Freestyle reader... 12.8. I have been checking every reading since then, and am finding almost all readings are out by 2mmol ... so what that means is that you are overdosing. I had to stay up all night because I had propelled myself into hypo territory. Turns out the sensor is wildly inaccurate.
Solved the other issues, nowhere else on my body is OK for application so I have just been rocking between one arm and the other. I'm careful when undressing so as not to catch it on clothing but find that around 10-11 days is when the adhesive starts losing its efficacy and thats when its most likely to just fall off. Which is as well, in a sense, because I found with the duds I have had, that it is nearly impossible to remove in the first day or two. One of the locations has still got the after effects... top layer of skin: gone. I apply a strip of micropore at Day 10 and that has seen it through to the full 14 days.
This last time I bought 4 sensors, 2 were duds, and have been replaced. I'll be applying the last one in a few days and will continue to check blood as well, and report back.
What I have learned is that the inaccuracy actually makes it very dangerous. its all good as long as you are staying in range (but then, you really dont need it) and if you go out of range, then you are treating for inaccurate readings, whether high or low. And so, finger stabbing becomes essential. The way I figure it is this: they say why prick when you can scan... but that is really false advertising, because you still have to prick anyway. And since thats the case... meh. $92.50 every two weeks is insane, for something you just can't depend on.
 The benefit of the reader, though, thats something... its rechargeable. so no looking for cr2032 size batteries when the shops are closed. It uses the same strips as the Optium Neo and also will read the ketone strips for the same gadget. Handy. So I'll keep using that once I transition to 100% strips vs sensor + strips...