Welcome to OCDO and the OC experience.
Carrying on your hip in any sort of manufactured (by you, some famous maker, or some cheap mass marketer) holster is good enough when in the car. It is generally easier to control there when turning, stopping, etc., as opposed to having to lunge for it as it slides off the seat or dashboard.
While you may get a few odd states in the Museum District (now just how is that distinguished from the Fan, except by real estate agents?), do not let that deter you from OC-ing. A part of the decision to OC is related to educating the public that possession of handguns is legal and poses no threat to them.
Thanks to state pre-emption law http://www.law.emory.edu/4circuit/nov97/967619.p.htmlNo city, county or town can enact laws regulating the possession or carrying of firearms. :celebrate Stop worrying on thatr score.
Your concerns as a new OC-er are valid. Try to come to the Richmond OC dinner next Tuesday 7/15 - see http://opencarry.mywowbb.com/forum54/12923.htmlfor details and the address. Everyone is welcome to attend, and it is a great way to meet folks who also OC or support OC-ing.