I'm actually college educated on electronic circuits and do electrical engineering as a hobby.
As long as the wires can't short, using the front receptical is functionally no different than using the back.
It's all one piece of metal, and it's not going to be somewhere that it'll be disturbed.
It may not be the best way, but done right it's not dangerous.
With a debit card that's your money at risk. With a credit card it's the credit card company's money.
Credit card companies are required by law to reverse fraudulent charges, but banks aren't.