Using a non-smart-card means you would have to trust the merchant not to just take all the Bitcoins on the card. This works for gift cards that are good at a single merchant but it doesn't really work for generic currency.
Yes, but then when you pay with a bank card, you have to trust that the amount you're authorizing is the same as shown on the screen, and when you use a credit card, you have to trust the number isn't being skimmed and stored somewhere. There have been cases of people opening up gas pumps and such and installing skimmers inside the machine, so you could never tell it was there.
The main thing is those machines are issued by banks, have various tamperproofing systems, and if you do get ripped off you have the bank to complain to. How do you be sure a random Bitcoin card reader is safe, and where do you go if you get scammed?