Some tinc clatifications

[Alessandro Briosi]

Hi all,
I'm currently happily using tinc in my networks.

I also use OpenVPN based on the customer requirements.

I though have some questions which I could not find a clear answer.

What I'd like to know is:
1. How to revoke a "node", simply removing the host file on the servers 
is enough? And one created by invitation?
2. Is there a way to let tinc ask for a username/password (like it's 
possible with OpenVPN)?
    (I know this might be complicated as one would have to have a 
centralized or synced user db, but that's not tinc business anyway).
3. Suppose I have 3 or more tinc "servers", is it suggested that the 
"hosts" directory be synced between thoose hosts?

Thank you.
Alessandro