You could probably start with a PHP IRC Bot: https://wildphp.com/
Configure and restrict it based on: http://help.twitch.tv/customer/portal/articles/1302780-twitch-irc
Then build a library/functions that will do the additional features you want, and call them when the commands are said in chat. The bot I linked already has some premade triggers built in for examples.
Maybe you could make a PHP Twitch Bot that accepts modules/IF triggers in a basic format, and distribute it. I for one would be interested.