Site Directives and Custom php.ini

The resync function is only needed when you manipulate data in the mysql database manually, it is not needed when you save chnges in ispconfig. So dont use the resync tool ehen sou did not edited omething in the b with phpmyadmin. As long as ou do changes in ispconfig, they get always synced automtically.

Regarding plugin programming, we dont have a tutorial on that topic. Take a look at the existing plugins to see some examples.