Rules question of the day, which I don't think we can answer without FFG but figured I'd throw it out anyway...

What happens if you Mind Wipe a Swarming enemy with extra cards attached? I'm inclined to think that Swarming is just the keyword that places other cards, and all the rules for attached Swarm cards remains the same, but...?

Yes, that seems like the most likely interpretation. Much as how Bonded only really matters when the card enters play. The wording of Swarming seems to indicate that being a "host enemy" is not contingent on having the " Swarming x " keyword, but instead is purely a function of having swarm cards underneath the host enemy. In the same vein, if a card that does not normally have the " Swarming x " keyword gains that keyword, it doesn't automatically gain swarm cards if it's already in play.

I agree that it could probably do with an FAQ clarification but I'm pretty confident in this interpretation.