I think there were complimentary yoga classes early morning. Otherwise personal or group classes for an additional charge dependent on number of participants.

I did not try, was just too lazy or too busy enjoying.

No, not all have that carved out view, some casitas are completely hidden in the vegetation, you should make sure to ask for it if it is important for you. Our casita was number 20, and it had a very nice view which I had not expected. I loved it! Others might want (even) more privacy (obviously it is theoretically possible that someone walking by sees your terrasse if you have a view, but really it is just theoretically since the few people that walk by walk down where the water edge is where nothing can be seen anyway).