tinc to create VPN between cluster nodes (at different datacenters) for High Availability

[John Griessen]

I've not really dug into testing tinc yet, but if you all will humor me in an uneducated blast of questions,
I'd appreciate it.

What can you do to keep tinc going if your high availability comes from cluster nodes being dispensable?
Can tinc run on the cluster nodes?
That seems like chicken/egg problem though to get tinc server installed and cluster nodes brought up...
If tinc needs to be providing gateways separately from the cluster nodes, how do you make tinc high available?
Install tinc on more than one simple VPS nodes?
Would this scenario always require your hosting provider to offer a kind of private network?