I think all the issues you listed are an issue for some folks and not as much for others. I wonder how Galveston will stack up against some of the much busier ports like Miami (when we have significantly more ships than we do now) when it comes to how difficult all those factors are (parking, getting to the port, etc.). I've heard lots of horror stories and accounts of things being super easy. Everybody's experience is different, I guess.
I would say that unless it's during one of the big holidays/festivals/biker ralllies, etc. I don't see an issue with there being sufficient restaurants, etc. On those weekends, though, all bets are off. Galveston is a madhouse during those special weekends.