First, report that player.
AFAICT you can't easily use Warlight to find someone's IP- only Warlight itself can do that, and even that can be dealt with easily. Usually, if you want to find someone's IP, you have to trick them into revealing it themselves- like
http://whatstheirip.com/ does.
You can literally download a free browser extension to mask your IP (be warned, though, that proxies and VPNs are going to slow down your Internet). Don't freak out. If you want to be much safer, use Tor or a VPN (I believe CyberGhost is free).
And someone finding out your IP isn't going to give them your literal physical address. To get anything really accurate, they actually have to ask your Internet service provider- which tends to only work for the authorities.
If you ever see something scary and technical, google it first. Try to find something on a trustworthy source- at least StackOverflow. DON'T FREAK OUT that easily. Every 14-year-old on the Internet who knows how to hide their browser history is going to claim to be a hacker. Just ignore them. If the threats seem serious, fact-check them; if they're threatening to harm you, you might have some legal recourse as well that you can mention to shut them up.
Apparently there is something called a MAC address, (not related to Apple Computers),
and these MAC addresses are much more specific and accurate.
Yes. MAC addresses are device-specific. But you don't need to worry about script kiddies, as long as you're careful about what sort of software you install and what sort of permissions you give it.
There are obviously a lot of zero-day exploits in many common software programs, and someone who wants to do so badly enough could find a lot of things out, but this is kind of like the sort of risk you take by just walking outside on the street- ultimately, use the defenses you can, don't become a target or inspire people to invest a lot of effort in violating your privacy, and don't freak out- if it comes to the worst, you have a lot of defenses on your side as well.
Really, you're made most vulnerable by the information you release yourself, willingly.
Edited 8/28/2015 01:08:48