Unlikely. But it is likely they will need to pay before resuming usage as a paying customer.

Yes, civil legal proceedings (and/or hiring a collections agency) are generally how debts are pursued in the United States.

They could if they feel it's worthwhile. Most companies don't, but most companies don't do most of the stuff mentioned in this article, because they're lazy. If they're not lazy they can absolutely follow up any unpaid debt in court, no matter whether you tried to use a virtual credit card or anything like that.

In German-speaking (DACH) countries the companies aren't lazy and they will take you to court and the court will make you pay all legal and court fees as well as the debt. It's a near certainty they will bother. In the USA you're hoping they won't bother and they'll be satisfied with just banning you as a customer. I think this is because each party pays their own legal fees in the USA.