The problem with Sealand is that you can't trust the people operating it farther than you can throw them, and they're not particularly small people. They are in a legally (and physically) precarious position, so if someone were to make a serious threat, there is no way you could expect them to be like lavabit and face them down.
(There's a new group trying to re-launch "HavenCo", although it has no real connection to Sealand; it's a VPN service and some mail and stuff run out of non-Sealand colos. I wouldn't touch it, myself.)
There is no solution to any of this other than pure technology. You want something where even the operators can't do worse than shut the service down, even if you have a gun to their heads. That's not technically feasible given current technology, but is a 6-24 months of development from being practical. And even with better technology, you end up having to worry about the entire stack, all the time -- constant vigilance is expensive.
(There's a new group trying to re-launch "HavenCo", although it has no real connection to Sealand; it's a VPN service and some mail and stuff run out of non-Sealand colos. I wouldn't touch it, myself.)
There is no solution to any of this other than pure technology. You want something where even the operators can't do worse than shut the service down, even if you have a gun to their heads. That's not technically feasible given current technology, but is a 6-24 months of development from being practical. And even with better technology, you end up having to worry about the entire stack, all the time -- constant vigilance is expensive.