Many of us do take our binders to the store with us. I put mine in the child seat spline side down and then I can flip through my pages to see my q's. With the system you have at home, it doesn't sound like it would be very easy to bring with you, however. My binder is organized by category and certain q's that are a definite use have their own BB slot (like Pantene Shampoo and Rice-A-Roni), and other slots have a mix of q's (like ALL Tylenol q's go in one slot). This takes a bit more organizing at home, but when you see the clearance rack at the store, it's so very simple to browse your q's to see what you have.
You'll prolly try a couple of different ways to organize your q's before you find one that will really work for you. Everybody's file system is different ~ even among binder users. Just keep reading how every one else does it, and one is going to click with you. There is only one way that is correct ~ YOURS!
BTW, my binder is always changing too, I'll find a different way to do this or that and change it for my better use.