> No idea why self-hosted software isn't `apt-get install` and forget.
Some of it is. But as soon as you want your services to be accessible from the Internet, you need to have a domain name and HTTPS. To run Limewire or a BitTorrent client, you don't need a domain name yourself because you use a central server (in the case of BitTorrent, a tracker) to help you discover peers.
All the popular domain name services and certificate issuers have APIs. All grandpa has to do is go online and buy a domain - which is a very reasonable step that grandpa can do. Grandpa, after all buys stuff online. But after that the self-hosted app should be able to leverage the APIs to configure all the settings.
Some of it is. But as soon as you want your services to be accessible from the Internet, you need to have a domain name and HTTPS. To run Limewire or a BitTorrent client, you don't need a domain name yourself because you use a central server (in the case of BitTorrent, a tracker) to help you discover peers.