For the UI, you could already use a view panel, although I agree actual integration with the sidebar would be nicer, and I'll probably add it at some point.
For the search event, one issue is that search queries are executed as the user types, so I'm not sure what would be a search query in your model. For example, if I search for "joplin", you might get the events "jo", "jop", "jopli" and finally "joplin".
I could easily add an "onSearchComplete" event in any case. I don't believe searchQuery would be useful though, since you could already get this info in the "onSearchComplete" event handler (which will get an "event" parameter with a "query" property).