We also returned to US from SXM yesterday and finally got home (PA), a couple hours ago. We were in Sint Maarten for 3 weeks.
I know that some are overly protective of SXM but should not take any of your comments personally. I will do a more detailed trip report when I settle back to normal life but do agree with your disappointment with some issues you mentioned.
1. More overcast, wind and rain than we have experienced in more than 30 years. no one but Mother Nature to blame on this one. We could not enter the ocean for a week because it was so rough.
2. Roads have always been bad and traffic has often been a mess. But, driving on French side is much worse than before. Potholes that can break an axle.
3. I cannot completely agree with your assessment of the airport. Since they have changed the upstairs/downstairs seating, almost everyone could at least sit down. Last year 2018-2019, you could not find a seat upstairs and you were not allowed downstairs until your flight was ready for boarding. It was better this year but certainly not what it should be.
4. Food prices? Shopped Carrefour's or Sunny Foods most days and was not shocked by any outrageous increases. I think for basic stuff (coffee, baked beans, hot dogs, bacon and eggs) there was no huge increase. Likely better meat cuts and classier cuisine there may have been higher increases.
More of a trip report at a later time.
Tom & Lisa