As someone not from Mobile but has met people from Mobile that are part of the world you describe I believe your statements to be spot on! You don't need to defend your POV as people disagree here all the time!
Many people that live in Mobile that aren't part of Old Mobile probably just go about their business, raise their families and don't think too much about what all is behind the decisions that are made in their city. I don't think this type of social structure is unique to Mobile or the South BTW its just that Mobile might be a more extreme example of a social structure that is relatively fixed and where a small group dominates the power structure in government and civic affairs. Going to Atlanta as an example you will certainly find Old Atlanta but there is a sense of movement amongst certain groups of people that are involved in government, civic affairs, business community and charity that might be considered a bit more socially open than say Mobile IMO.
What would you think would happen if a member of Old Mobile might be involved some way with DNV case? Would that be a reason to pull the CCTV from the Shell station? Could that be why there has been no substantive public information on the case in weeks? Could it be why the local press hasn't been taking an investigative approach to this cast at all and seems to be going through the motions of reporting on this case? Is what we are seeing or not seeing in this case the result of Old Mobile?