DOX'ing is not hacking
IP addresses are not passwords
I'm not sure whether you can exploit someones conputer through the Internet with their IP address to collect passwords or whatever, but that's a new issue. With someone like Nate, it's unlikely.
DOX'ing is very easy to do. Anyone can do it, with very, very basic knowledge of technology. There are multiple websites that can trace IP addresses to locations, and from these locations on other websites, you can get info on who lives there, etc.
It's very easy.
I doubt it's illegal considering anyone's eyes can see this info.
While this is scary, and you may feel insecure, you need to understand a simple thing- any website you visit can gather your IP and DOX you, unless you use a proxy, which I believe is false.
Don't worry about anything, you'll feel better.