I don't think this is the "Continental" way at all. It's actually the "United" way, but they are using Continental colours and logos to mask this fact.
Totally not true. In the past (and currently) United never has charged our credit cards, either when reserved NOR when confirmed. It's only on when the flight actually is in the air!
It may be the idea of a UA staff member, but it's not the UA way.
But it is sleazy! Trashy. Poor business practice.