Hey there, Dave! Thanks for getting in touch and great questions.
First off, the volume of events. We do take the issue of performance very seriously and believe our plugin is very performant and able to handle some pretty intense work loads as quickly as possible. That said, I think there will always be some sort of cost when dealing with a huge number of events in the range you are targeting. I think the best way to ensure that the plugin performs to your expectations in this case would to use the free version and test from there. The free version is the core for all the other add-ons, so if it can handle the load, then everything else will follow suit.
In regards to the display of a day with many events–you can actually set how many events you would like to display. Anything above that number will display a “See All Events” link that will target the full list of events for that particular day.
Does this help answer your questions? Please let me know. 🙂
Cheers!
Geoff