If it will start up in "Safe Mode" just fine, then there is something (software related) on you device that is causing the problem. The system restore and reset, unless they were wiping all things on the device, then they would not have removed any software, virus, malware, etc., problem.
From "Safe Mode" have you checked for malware, viruses, newly installed software and updates? That is where I would start. If that doesn't resolve it then I would look at doing a full restore of the system. Which will require you back up all your personal stuff somewhere else. Another device, cloud account etc. Otherwise it would all be lost. Then try reinstalling the system from scratch.
But that is a last resort. Start with checking things and scanning the computer from "Safe Mode". And make sure your program can scan for both viruses and malware as they aren't the same.
Well, I ended up doing a full system restore and it's still happening. Is there any chance that this isn't a software problem? It's bizarre but I can't think of anything else at this point.
Also, besides the point but; there was a guest account that I didn't make on there. I assumed it was part of some malware, but is it possible TSA messed with my laptop? Are they allowed to do that? Not trying to sound paranoid but it would explain a lot.
You mean wiped the computer of what was on it and did a fresh start of the OS and original software? If so, then there should be nothing left on it from before to make it a software issue. However, if you didn't do that, and left anything at all on it from before, or installed anything already, then it could be software.
Well, I used the built in Windows 10 Reset PC option, but the last step of it is rebooting and reinstalling Windows which it obviously can't do. Is there a more aggressive way of wiping it short of an electromagnet?
You can get a CD/DVD/USB with the OS on it and start it from scratch. That should allow for formatting and installing it all fresh. You can get a copy from the manufacturer, often free from their site or for a price if they are shipping something. You can also try going through the following link, and creating your own.