We were at Vistana Villages during the first full week of December. I didn't ask about availability of villas in all the buildings in St. Augustine Village but there were no visible signs of construction anywhere within Vistana's walls. And there were cars parked in the parking areas in front of the newest buildings so I figure that they're in use. So, please accept my comments based on what I observed rather than having garnered information from staff at the resort.
Referring to your map link...
The Amelia section is comprised of those buildings closest to the road - 27, 28, 29 and 30. Buildings 23, 24, 26 and the two buildings in the shaded "Under Construction" area are in the St. Augustine section. Those Under Construction buildings are up but I don't know if they're in use yet. The ground floor areas of Building 26 and the one to its left look to be in a state of being prepared for installation of resort amenities - workout room and some type area store or deli would make sense for those locations. The Bella Florida section is comprised of the most buildings (numbers 1 through 11) and Key West includes buildings 12 through 17.
You're correct that the pirate ship is located in the St. Augustine pool area. The resort is very cautious about access to the St. Augustine pool area and they chain lock all of the access gates in that area during hours other than those posted "open" hours. I assumed that that was their way to ensure that children wouldn't be able to enter when there isn't any supervision (the ship is pretty attractive so I understand why a child would be attracted to the area).
I don't know about the height minimum for the St. Augustine pool area but I tend to agree with you that it doesn't make any sense at all to apply a 42" minimum to use the pool area. Such a minimum for the pirate ship slide surely makes a lot more sense. You might have luck in getting an answer to that question if you posted it at TUG (Timeshare Users Group) in either the Starwood Vacation Ownership or Florida forum -
www.tug2.net.
On section/building preference - this resort is quite compact. We stayed in Key West as we'd requested through Diamond Lane. It's less than a quarter mile from the building we stayed in (#12) to the pirate pool - a five or six minute walk - and no more than half a mile from the front of the resort (security booth) to the back part of Key West.
I point this out as the dedicated two-bedroom villas in Key West are the largest (by a small margin) at the resort. Key West's are 1126 square feet, Amelia's are 1102, Bella Florida's are 1080 and St. Augustine's are the smallest at 1070. Fifty square feet aren't likely to be a big deal unless your party pushes toward the upper end of occupancy capacity but having extra space to stretch out in is, IMO, always nice.
This is a nice resort. We'd go again if one of favorite resorts wasn't available.
Dick Taylor