Yes, in the past we've intentionally waited to board after 1pm so we could go right to our cabins and set down our stuff before we go off to explore the ship. I'd much rather have a relaxing lunch on land than to battle the masses at the Windjammer or other locations. So yeah, don't mind the 2pm check-in one bit. Plus, it's an 8 night cruise, so getting on the ship a few hours later is no big deal. We have LOTS of time remaining on the cruise.
However, yes the shows are the ONLY thing I'm concerned about. If you truly have most of the 1st day to reserve shows, then that would be great. The shows are very important this time because my parents (mid 70's) are with us, we well as my sister and her college age daughters. They have never cruised before (and who knows when/if they will be able to again) so the evening entertainment is a huge part of their experience that we don't want to miss out on.