Hello. Thanks for mapping.
About High buildings. 
You've mapped several times a building as 3 separate buildings.2 x different levels as 2 buildings
1 x a siding as 1 building.
Check this guide to see how these buildings ought to be mapped.

https://docs.google.com/document/d/1z7uDwYm4oNmlexHIhJxGCjPpNhCQAgRia5aEJr_4MwM/edit?usp=sharing

Best regards
