Well i couldn't sleep....
So here goes... I've managed to get the plugin to a runnable state and it should work with no problem. Just unzip it to plugins folder, and go to options and set the calendars.
By default you type "cal " to input an event, "cal todo" to input a task. Dates and times should be recognized normally. You can view existing events or tasks by typing "cal todos" and "cal events". I am not sure if it works correctly but you can do a "cal sum" with additional dates or categories to get a total time of events for a period of time. You can specify categories with "+category", location with "@location", calendar with "!calendar" and separate description from summary with "|".
If you take a look in the advanced options window (found in plugin properties) you can see a list of calendars along with their name(this is the name the plugin uses to identify calendars), some keywords and some regular expressions. Set the correct calendar path or you'll get an exception. I think that other fields are self explanatory but here goes, you can set which keywords you want to use for adding a task, viewing a list of tasks and events. You can also set regular expressions for recognising dates and times, calendars, locations, categories etc. Defaults work pretty fine so there no real need to change them unless you know what you are doing.
- first calendar in settings is considered default so if no calendar is specified, that one is used.
EDIT: I found an error. i forgot to put the dll in the package..... so here is the updated package.