I don't mind questions

My old machine didn't have adjustable feeddogs (couldn't drop them either) and it was fine.

On my newer machine I usually sew with them at a level 3 and they work fine on the cards. I'm guessing you'd need to play with yours. I've not tried real paper... the card stock is firm and stiff - kind of like lots of layers of thick interfacing. I just sew them where-ever my feed dogs currently are. If your machine is super tight, then you may need to turn them down a notch.
Does that help?