We just got back from a 2 week stay at Mount Vernon. Our studio was in the Antigua building, 3rd floor, great view. Here is a photo taken from our balcony.

https://lh3.googleusercontent.com/-Ah01d...2/IMAG00446.jpg

The seaweed you see in the photo was typical for the entire time we were there. They raked the beach with a tractor or by hand occasionally so there was always some clean sand between the pool and waters edge. However, very few people used the beach. There was no odor from the seaweed.
Some condo owners have access to reserved parking spots but most parking is first come, first served in lots with undesignated spots. We were offered a reserved spot for an additional fee but chose to take our chances. We managed to find parking in the upper lot nearest to our unit most of the time but we did have to use the lower lot a few times. This may not be the case during high season.