From our research, it seems that a lot more of the hardware is running linux than we would've expected [1]. This makes linux a great starting point - but you are right there's other platforms to look at too.

Regarding data use - you're completely right. In previous production IoT projects we've worked on we've had in excess of 10X more debug data than actual useful information coming out, lest we're not able to debug problems! We've got a few tricks up our sleeve, the main one being that this only sends data when there is an exception.

[1]: https://ianskerrett.wordpress.com/2017/04/19/iot-developer-t... (Point 4)