a) My family doesn't understand exactly what I do. All they know is that I work with software. They don't care about the fact that i'm in R&D. For them working in software means i'm qualified to install windows.
b) This is the part I don't get. I work in a company with more than few thousand employees worldwide and our IT department has already started testing for the general rollout of windows 10 which will start somewhere around April 2017. I've even talked to a few guys in IT and none of them seem to have a problem with windows 10. I've actually quoted comments I've read here and on other websites to them and the "tin foil wearing conspiracy theory nut job" statement is actually a quote from one of them.
c) Yes I've seen the new T&C. I understood all the technical part. And any questions I had about the legal side I asked my friends in the legal department of my company.
So basically my judgment that windows 10 is safe to use for both me and the people I know is not just based on my understanding alone. The opinion of multiple employees of my company have gone into this. And frankly I know the people I work with. I know what there credentials are and I know how good they are at their job. And if those people say everything is ok then there is nothing anyone on any site or blog can say to change my mind.