does not work properly

I’ve used this plugin on several sites and all of the things you mention work fine for me. OK, you can’t copy events out of the box, but they’re just another post type, so any of the duplicate post plugins will allow you to copy them. But other than that, I can change dates and times and can include or exclude recurring events. Note that if you have a recurring event, you have to tick a checkbox before it will let you edit the dates and times, so maybe that is what you were running into.