2)There's a lot of card companies out there. Find one that doesn't charge fees. That's trivial.
4)I've had other experiences, with a hold far greater than the rental amount placed on a debit card. It was a major rental car company- Avis? Hertz?
5)CC debt is the first thing to go in bankruptcy. So if you're really in that position you want lots of it and no extra liens on the house.
6)That doesn't help you if they decide to flag your card and shut it down. It will take a few days to get the new one, and in the meantime you can't use the old one. That's assuming you're in the right place to even get it. Would have totally sucked to not have had a backup while on my 3 month trip to Europe. Or when they flagged my card right after I moved because I used it in the same hardware store twice in an hour. Never rely on one card.