You’ll face a high regulatory and liability burden, but neither of those are insurmountable (note that I am not a lawyer or financial advisor and this is not legal or financial advice). Liquor license to serve drinks is the first that comes to mind. Then there’s the risk factor that running a bar involves dealing with unsavory people (people who start fights, harass, other levels of petty crime and violence). You also need to screen guests for valid IDs.

You need a rent-a-bouncer service for your hosts, too at the very least.

Again, not impossible but difficult (and solving the difficulty is the whole value prop of a business). Consider synergies with other event organizers, especially in the music scene.