Does national car except debit cards, and do they require a deposit? How much deposit do they require on a weekly rental?

Actually they do with a deposit transaction

Not sure about debit cards but a deposit is required. When using your credit card, the charge is removed from your credit card upon return of the rental car. It's really just a temporary hold

Our deposit was 200 or so

Every company has difference policy. I knew some rental companies that they are not accept debit card at all.just check before rent ur car.