0. https://wiki.recompile.se/wiki/Mandos - note that you'll probably get an SSL warning because the site uses CACert.
The canonical link is (https://www.recompile.se/mandos), which currently redirects into our MediaWiki instance.
(Regarding CACert; we are planning to move to Let’s Encrypt whenever they become available, but for now CACert is at least better than self-signed.)
2. CAcert was chosen when the system was used for different purposes, in a different environment, by a different audience, and at a time when Debian shipped browsers with CACert’s root cert included. After that, it’s just been inertia.
3. I quote from the StartSSL F.A.Q.¹: “The Terms and Conditions of StartCom and the StartCom Certification Policy requires subscribers to provide the correct and complete personal details during registration.”. I generally don’t create accounts with external services, and as a sysadmin, I can and do run everything myself.
As with DRM, it is impractical to store both a lock and its key in the same place and expect it to be secure.
That’s what I said to a friend of mine when we had numerous servers with encrypted disks and frequent power outages requiring us to type in passwords. He then suggested many different schemes to fix this, each of which I shot down as being insecure. Then he came up with something which I couldn’t shoot down, and he made a first proof-of-concept implementation, which is how Mandos¹ got started. This was many years ago; Mandos has since become available in Debian and Ubuntu; just do "apt-get install mandos".