4 questions about tinc's VPN

[EleGoS]

Hi there!

I'm totally new to the concept 'self-made VPNs' :P
I've discovered tinc and I think it's not as easy as hamachi, but not so 
hard as OpenVPN :D

Now: I've got 4 questions:

question n.1: I'm behind a router. This router is configurable, but I'm 
also behind a provider's NAT (private IPs with a common public IP). Will 
tinc work, or it will do as hamachi does (problems connecting to me)? 
(in hamachi there is a 'yellow' indicator on me for users of the same 
provider [passages: |private IP| -> |public IP| -> |hamachi server| -> 
|public IP| -> |private IP| -> |router's private IP|])
question n.2: a tinc VPN uses the server's bandwidth (so all the 
transmissions pass from the server) or is a P2P system (the server only 
re-addresses the connections)?
question n.3: if a client enters a server, does the client 'see' all the 
others connected to the server?
question n.4: what about the public and private keys? What to give to 
the clients? What the clients must generate?

Thanks ^^