If as you said, you are not willing to use bitcoin in public, it means that you do not want people to know you are a bitcoin investor. If everyone is like you, how can bitcoin become a currency, a means of payment when everyone hides that they own bitcoin? We always want bitcoin to become more popular, always want people to know more about bitcoin, but meanwhile we are afraid to use bitcoin or spread bitcoin to others. How can bitcoin become popular?
BTC is already very popular, you don't have to tell everyone about BTC or that you use BTC before it can become a currency. People spend BTC daily, either in their local stores or online and they don't have a problem doing that as long as they are protecting their privacy, by either not reusing addresses, or not using addresses that holds their main funds for payments.
I have never before seen a physical BTC exchange, though if i have one around me, i may consider using it, because whatever threat you feel after using such exchange should be the same as when you walk into a fiat bank or use a fiat ATM, though i get it that in some areas where BTC is not too popular, people think that whosoever uses BTC is very rich and they may become a target.