True that. After looking through the script in more details, I wouldn't recommend running without checking. I thought it was doing just basic ssh + firewall, but it does a lot more things, so probably better to run piecemeal even for non-experts.

Maybe this could be turned into some interactive script that explains a little (in beginner-friendly language) what each step does? It would be also nice to have a log of which steps were performed, and instructions for the undo-step in case users want to go back... wishlist.append( ^ ).