The indoor/outdoor pool by the lake is heated; the big "Wakoola Springs" pool is not.
I expect you're right. Most of the units there are the 1190 sq foot 2 BRs. Buildings 3 & 4 have the 1343 sq foot "Deluxe" 2 BR, the biggest units short of the presidential, but also the 1034 sq foot 2 BR "standard, which are the smallest. If you're trading in through RCI, the Deluxe are the Oasis Lake ones that sleep 8, and the standard the Oasis Lake that sleep 6. Building 10 has all the Presidential and Superior units, meaning those either face the road or the pool (I think there are some regular units in building 10 as well but I'm not sure). All the other buildings have just the regular ones.