I've found out with other things that family needs to be told to keep personal details private from other immediate family. My brother has gotten better about respecting my privacy regarding things like GSM stuff by default, but still assumes similarly queer friends are free to be told (and I believe giving a lot of personal details related to that, not just the label; tbh, I'm actually fine with that, but it still feels like something he should have asked first about).
With autism I'd especially assume no privacy unless explicitly requested because I'd assume people already knew anyways. A diagnosis doesn't really change that.
Just back up any important files. I've had to do many reinstallations because of accidentally breaking things.
For pdf software, using wine is an option. It also has been a concern of mine with switching, but it seems the software I've been using (PDFxchange) works fine with wine.