Hey Jasmin,
I don’t know that we are the solution you are looking for. The only emails that are even remotely attached to the calendar are through the ticketing solutions and are merely notifications, not true emails. I’m not sure what you mean about embedding social sharing buttons, but I do know that is not something that is included in our calendar plugins. It is likely something you could add to your site through an additional plugin, however. Our event pages do not really accommodate comments, either. Adding something like Disqus is most likely possible with customization, but we cannot provide support for that.
You’ve got a lot of great ideas there, but I don’t know that we’ve got the features that you need to make it happen.
– Julie