Ha, don't go back to that store.
Bindings are very important because they help you maintain good posture on your snowboard and they can make all the difference in helping you carve. Also, they need to securely keep your boots snug so that all the power you are exerting through your feet goes directly onto your board so it is moving the way you want it to.
Bindings also come in different styles, such as regular or toe cap straps. I also know that Flow make a kind of "step-in" binding that is basically one chunk of fabric that you can strap over your boots in one step. All of these styles are preferred by different people. Personally, I prefer the toe cap straps which fit snugly over the tip of the toe of your boot. I think it gives me much more power and drive into my toe side turns.
You also need to get a good stance with your bindings when you mount them. If you have shitty bindings, your feet and ankles will be hating it and you probably won't be able to maintain good control over your board.
Good luck with your purchases. BINDINGS DO MATTER