I mean, you have to be pretty comfortable and somewhat casual in an orgy - it isn't like someone is going to tip their top hat and say "Perchance, madame, may I gaze upon you from below whilst delivering my tongue?"

I mean, maybe someone would, but it would be with someone they know and kind of jokey about it.

But this:

obviously I would never touch or invade someones personal space without verbal consent.

You might not, but some do behave that way. Its gross when it happens, and generally speaking, that person wouldn't be invited back (as long as the person running the event is made aware).

So really, yeah, you'll need to be comfortably casual. You're going to have sex with them, not ask them to take you to prom first.