If your laptop has hardware secure erase, that's pretty much the best option. However, if you're ordering personal amounts, LE isn't going to spend weeks doing a forensic analysis of your computer. Something to think about, but if you can reinstall the OS for free, sure secure erase the hard drive. You could save your PGP keys to a thumb drive. You may not be able to boot from a thumb drive, but you can plug one in after booting and save data to it. Just copy the .gnupg folder that's in your home folder (it's a "hidden" folder, so you'll have to do View -> Show Hidden Files in the file manager). After each boot, delete the existing .gnupg folder (if it exists; it may not until you use a PGP program) and replace it with the backup copy. You'll have to update the backup each time you add other people's public keys. It will be easier in the long run to use Tails USB. I've heard of hacks that allow you to boot thumb drives on restricted Macs, but I don't know the details about that. Depends on where you live. In China or Iran, you can't access public relays at all. Under some despotic regimes, you may get a knock on the door. I don't know of any western country that does that, though. It's not illegal to use Tor, and nobody is going around kicking people's doors in for using it. I've been using Tor for over 5 years without a problem. However, you can hide your Tor use with a VPN or bridge, if you want to.