There was a recent trip report that praised Holland House for it's location, rooms, view and beach in front so I would say that staying in Philipsburg is not bad at all. It is full of many restaurants, gift shops, and casinos. If it were me though, I would not wander far in the evening except to drive to other parts of the island like Simpson Bay, Maho, or Cupecoy where there are plenty of people enjoying the nightlife situated in those areas.
For your extra nights, for a really nice place, you could try Mary's Boon, although you could find places cheaper which I believe you are looking for. Also, there's the Royal Turtle Inn in Simpson Bay. The Royal Turtle price comes with breakfast, if I am not mistaken. Then there is another place along Simpson Bay which people said was very nice and is great for a few nights but the name escapes me for the moment. Maybe someone will pipe in and advise.
For fishing, your husband can sign up at Lee's (it's a restaurant but has deep sea fishing excursions as well) in Simpson Bay. I don't know how much it would cost now but a few years ago my brother paid $125 as long as they got 3 other people to go as well. Lee's did get 3 other people so he went for a 4 hour fihing trip.
Life is not a child's game of follow the Leader. Instead, life is more about finding one's own purpose in life....your life's plan, and then making a positive difference on earth.