They are one and the same. Whether it's written as Comic-Con or Comic Con, it represents the same gathering of comic enthusiasts and the showcase of all things comic-related.
It's hard to say for sure. Comic Con events are often planned and announced closer to the actual date, so we might have to wait for more official information.
Comic Con 2021 did happen. But it could have had changes in format, number of attendees, or featured content based on the prevailing conditions at that time.
No, Comic Con International doesn't own Comic Con. Different organizations or entities might be involved in organizing and managing various Comic Con events.
Comic Con and Comic-Con are basically the same thing. They're both events focused on comics and related pop culture. Maybe the only difference is in the specific location or organizing team.
It's hard to say. Different comics have different settings. You might need to check the details of the comic you're interested in to know for sure if there's another entrance.