You know, if you are not operating a retail sort of establishment and are just providing a service, you don't have to worry about a lot of those details. I sew and do alterations and make special order quilts for people from my home without having a "store front." Much of it is done by mail, but if I am doing local alterations, the client just uses my bedroom as a fitting room. I don't have a need for extended parking, and traffic on our street is not increased because of my business.
Basically, in your situation, people are dropping off quilt tops and you quilt them and they pick them up. I bet you are in a similar situation as I am. I would not try to set up a "customer" area at all.