> Current F13 expansion cards will pull out sometimes when you remove a USB cable
That feels like a defect in your particular machine, not a design flaw. With my laptop, the cards are actually incredibly difficult to remove most of the time. I can't imagine one of them coming loose by accident.
I own three and they all do it on occasion. Usually with a USB cable that tends to fit more snugly in the port. I mentioned it in another post in this thread but I think the button on the bottom gets pushed accidentally while being handled and the latch becomes unseated.