Thanks. Please check /var/log/nginx/....error.log to see exact cause of the 403.
P.S. you didn't have to paste wordpress-specific custom config bits into the phpmyadmin configuration.

1. Run chkconfig ajenti on to enable autostart for Ajenti.
2. Are you trying to access websites that you have configured with Ajenti V?
3. Zip your /etc/nginx/conf.d and send it to e@ajenti.org along with /etc/ajenti/vh.json

Yes, you can use any wildcards (examples: http://nginx.org/en/docs/http/server_names.html#wildcard_names). Also, you can mark one of the ports in websites as Default, and it will receive all requests with unknown domains on this port.

Have you created a website for www.website1.com / added a www.website1.com domain to some website? If www.website1.com domain is unknown to NGINX, it will point you to an random website of yours. Note: 'www.' is a subdomain like any other.

'permanent' will instruct NGINX to send '301 Moved Permanently' response.

Please also post output of pdbedit -L -d0.

You can do this by adding another website for www.domain1.com, and adding this custom website configuration:

rewrite ^ http://domain3.com$request_uri permanent;

(from http://stackoverflow.com/questions/7947030/nginx-no-www-to-www-and-www-to-no-www)

Is the D-Bus (/etc/init.d/dbus) service started on your system? Try restarting it and then restarting Ajenti.

Try running pdbedit -Lv -d0 -u nobody by hand

What problem exactly did you encounter?