I've never cared for the notion that the Enterprise-A was any other ship, even the Yorktown. Scotty says "new ship," not "new Enterprise," and I believe that's enough to indicate it's a new ship.
As for her decommissioning, I think it was a missed opportunity to go with a simplified idea simply so that the general audience would understand that this was the last mission of the old crew. Kirk's final log says "This ship, and her history, will shortly become the care of another crew." There could have been room for an interim crew, which I go with in my own head canon, which doesn't acknowledge the existence of Generations as it was filmed.
As for those old DC Comics, they were glorious. I was born in '76 and my brother's comic books, TOS reruns and the TOS films were a huge part of my childhood. I read those issues with Kirk and crew on the Excelsior once my brother moved out (he didn't let me touch his comics!) and once I began collecting and reading on my own, I read the Peter David relaunch and the TNG series by Michael Jan Friedman. Those were and remain excellent comics in terms of writing and art. I highly recommend picking them up if you've never read them. I still have mine in a longbox somewhere...
As for her decommissioning, I think it was a missed opportunity to go with a simplified idea simply so that the general audience would understand that this was the last mission of the old crew. Kirk's final log says "This ship, and her history, will shortly become the care of another crew." There could have been room for an interim crew, which I go with in my own head canon, which doesn't acknowledge the existence of Generations as it was filmed.
As for those old DC Comics, they were glorious. I was born in '76 and my brother's comic books, TOS reruns and the TOS films were a huge part of my childhood. I read those issues with Kirk and crew on the Excelsior once my brother moved out (he didn't let me touch his comics!) and once I began collecting and reading on my own, I read the Peter David relaunch and the TNG series by Michael Jan Friedman. Those were and remain excellent comics in terms of writing and art. I highly recommend picking them up if you've never read them. I still have mine in a longbox somewhere...
, this is not "space the final frontier, to explore new planets and civilizations, to bold go...". At the start of the movie, I assume the Enterprise is doing the exact same mission since they have the same gaseous anomaly mapping equipment on board and are close to standing down in two months (about to finish their mission the same as the Excelsior).
at the moment. If that "threat" goes away plus little-to-no exploring deep unknown space, then Starfleet can't justify it's large fleet of ships, so, mothballing will be the plan in the future after the movie. Starfleet will try to muster limited deep space exploration missions occasionally such as the Stargazer, but it'll take ~+65 years with new faster and longer mission ships (i.e. Galaxy Class ships) to get the technology make exploration of deep unknown space feasible again. YMMV 