As for the neighboring states, I have the FL and VA CCW but they are not valid in MD. Only a resident MD card is legal here, just like in CA. If I had a MD one it would cover me in other states but not the other way around. Pretty dumb.
The peperwork will die a slow death and I'll have to keep waiting until they pass the Shall Issue Bill that hits the legislature every year (Hell freezing over comes to mind) or I can move somewhere else (see earlier snow/ice). I'd love to move to AZ but it isn't happening any time soon.
The denial not meaning anything: The Trooper said they would only look at the original paperwork to see why it was denied and that if it wasn't for cause (felon, protective order ect) it would be filed with the new one as additional documentation not as a bad report.