Bind 9 configuration

[Stayvoid]

Hi,

(I hope that it's fine to ask about issues connected with the previous
version of bind.)

Could you confirm that my settings are correct?
I'm using this guide (my configuration scenario is primary master server):
https://help.ubuntu.com/community/BIND9ServerHowto

(I can't attach the files. Sorry.)
/etc/bind/db.example.com:
http://pastebin.com/raw.php?i=U9CYqDyj

/etc/bind/named.conf.local:
http://pastebin.com/raw.php?i=cTuuwPNA

Questions:
1. My /etc/hosts doesn't contain anything related to ns.example.com. Is this OK?
2. How to configure bind to support IPv6?
3. I have joe.example.com in db.example.com. Will it be my email
address (e.g. joe at example.com)?
4. Is it possible (and necessary) to have several ns (and mx) records
on the same machine?
5. What should I write in /etc/bind/db.<the first octet> file? Could
you provide an example?
6. Is there a need for additional tweaking?


Cheers