Couldn't find these in one place, so here they are for any other newcomers. Posting them to see if anyone has something to fix/add?
Sea-level is at 20m.
Access-lists are enforced up to 15m above ground level (without an added security script).
Flying/Hovering more than 50 meters above ground level will cause you to drift downward at 3.39m/s. More than 100 meters it increases exponentially to 17m/s drift.
Highest flyable altitude is 170m above ground level (without tricks).
The cloud layer is at ~160m-240m.
Highest altitude for anything is 768m.