I will do some testing on my local machine with the IIS SEO toolkit and try to resolve some of these for the next release of Event Calendar Pro.
Probably some of the solution is going to involve adding noindex/follow meta tags on some of the view pages like week view and day view so that search engines won't try to index them.
The reason these things give violations is because they appear to have the same content on different urls anf this is what causes the canonical warnings. For example the content on day view and week view is identical for every empty day or empty week. Since these views really just provide links to the details they have no seo value for them to be indexed, really you only want the detail views indexed.
You definitely do not want multiple pages to have the same meta description (that would produce more warnings) and don't really need meta descriptions at all on the pages that don't need to be indexed such as week view and dayview and monthview. Only the detail pages need descriptions and the main page where ECP is loaded you can put meta description in page settings. On the event details you can already add meta descriptions but they should be unique for each event.
Best,
Joe