> lasts a lifetime

You need to renew the license every 10 years, but as long as you renew you don't need to take a test (which is maybe what you mean by "lasts a lifetime").

Yeah depends on the country/jurisdiction - in Canada, an amateur radio certification is valid for life, and doesn't require any sort of re-testing or paid renewal or anything. Pretty nice. One of the few times the government has really done something right, IMO :)

In the US, it lasts a lifetime but you have to tell them you're still alive every ten years. This is free, but if you don't file the form, your license is no longer valid.

In a lot of places your name/address is publicly linked to your callsign when you have a HAM licence, in databases anyone can search.

Which is absolute shit.

If you're in the US, you can use any address you can receive mail at (work, a PO box, mail forwarding service, etc). I used a cheap mail forwarding service (it actually doesn't charge a monthly fee, just shipping and I never get mail there anyway). The important thing is to get this setup before you even get your FRN because the change history of your license is also public, so once your address is there, it's viewable forever.