Honestly I take out these sorts of boats at least once a week. I do not take anything I cannot fit into my pockets inside the water tight bags. You are in a pretty much open **** pit sailboat. The chance of you capsizing is pretty much all up to you unless its blowing 20+ knots. You do not need to worry about keeping your things dry if you know your points of sail and dont tack past 90 degrees or Gybe from broad to broad. If you start to heel too much, just release on the main and turn into the wind.
Like I said if it isn't blowing at least 20 knots then on a boat that size capsizing is purely voluntary.