You could do a lot worse than an HR53. The draft would be a bigger concern to me than the mast height. Missing out on the ICW wouldn't bother me in a boat of this size, heck with that much waterline and a good forecast you coud bypass most of the east-coast ICW in just 3-4 days and save yourself weeks of slogging along under power. But having to anchor so far out in the other places you might visit would thrill me a lot less. It wouldn't be a dealbreaker for me, but it would give me MUCH pause.
This is a fairly rarified cross section of boats that you're looking at -- one I'm somewhat less familiar with than say the 30-45 foot range. I recognize you've pretty well zeroed in on the HR53 (be sure to ask about that windshield glass issue I mentioned in the other thread), but this is a big investment and if I were looking in this size range there are a few other boats I'd want to compare with at least for a sanity check:
Amel: 54, or Supermaramu 53
Malo: 46 (yes, it's smaller, but in my opinion they are more creative with their interiors than HR). http://www.maloyachts.se/
Najad: 490, again more creative/flexible use of interior space than HR. Optional 6'7" draft. http://www.seacraft.com/najad490.htm
Morris: Why not give one of our homegrown's a good look. Chuck Paine seems to have been able to get away with much more reasonable draft than HR/German Frers. New might be out of your range, but take a look at some of the used offerings. http://www.morrisyachts.com/sail/51/
Best of luck with your decision.