You don't need to cover all of these problems either in MVP or later.
What is the "dance" that leads to a great "event"? Broadcasting location is a feature of all services. Broadcasting the right event to the right people is something that is not a feature of any as far as I can tell.
So, what is the social dance? Doesn't it go like "I'm going to bar X, who shall I call/text? If I text Y, then I won't text X because they get into heated debates and derail the evening. Plus, Y is usually busy this time of day". Or you're with someone "Let's have a drink. [other person]: this is Z's neighborhood, mind if I text him to tag along? He's cool[you don't know Z, but your friend vouches for him]"
Isn't paying attention to these details that leads to a good event?
The event (vibe, time, place, optional description, people) must fit. And then you can tweak these levers: if I set a vibe and I don't care about time and place, which people will I invite?
If I set a list of people, which combinations of vibe, time, and place would be good?
What am I optimizing for? Good time, or number of "attendees"? Is it destined for a context where I know the attendees, or am I just throwing a big party and everyone is welcome, as long as they are in the circle of people I trust.
This needs to be super, super simple to set up. As simple as texting someone.
Maybe a simple use case is for events that are happening right now, then refine to scheduled events. Cold start:
I click on the app. I enter a description "Going for drinks at Foo" in the field. The app displays list of contacts to invite. I check three or four. Hit send. It sends them a text message (they don't need to have the app) with a signature "Sent with Social Dance" or "Sent with Inner Circle", or let's be douchey "Sent with innrcl".
What the hell is Social Dance?
The application then remembers that context (vibe, time of day, "drinks", Foo [place], people you invited, location) for subsequent recommendations.
You train your application like that so it'll recommend you set up events.
Later, you can have a map with different possibilities "Watch tonight's game at the Foo Bar" or "Listen to X playing live at Tak the Bar". Click, it'll prefill a list of people to invite. You check it, if it looks good, you go for it.