Regarding passing data onto others. I haven't heard this. Where did you read it?
I was reading some of the stories and blogs about Windows 10 and the issues were raised repeatedly - for example see link. I gather much of the data collection can be turned off, but what functionality is sacrificed when these features are disabled? I just get the feeling that many companies - not just MS- are playing a game along the lines of 'you do not have to give us information, but if you don't our software won't work'. That might be fine for a web site, but it would be much less so for an OS. Also, I wonder how secure the information will be in transit to and storage in MS. But, like I wrote above, I was just curious to see what knowledgeable people make of it. I'm suspicious but perhaps it's not that big a deal.
EDIT: quoted a more reliable link; cleaned up spelling