Dangars, what makes a music store great, is all of the personal service that you describe above. Unfortunately, there are very few of them left. The catalogue sales companies and big chains are making it really hard for these kind of stores to compete. The low prices that they are able to run, make it hard for the good stores to stay in business.
This is a dual edged sword for you and I. We get lower priced instruments, but often, don't get the service and personal relationship that we would like. I am as guilty as the next man, when it comes time to buy, I will look for the best deal, often on line.
There is a small mom and pop store in Irving, Texas that I try to stop at when ever I pass through. I know it is n't much, but I try to at least by strings and smaller items that I need there to keep some business flowing there way. They have a guitar technician that is really good and I bring all of my pro set ups and pick up changes to him as well. If I don't do it myself.