From your photos one of the issues with your maple is likely powdery mildew, a common problem, especially after a wet period in June such as we had. See more on this at https://pnwhandbooks.org/plantdisease/host-disease/maple-acer-spp-powdery-mildew
and https://ask2.extension.org/kb/faq.php?id=149879 In general this problem is not a major health issue.

Regarding symptoms such as brown spots, leaf curl, small leaves, premature leaf drop - there are a variety of possible issues that affect maples. There has been an increase in maple dieback with some or all of these symptoms. For more information see:

https://www.oregon.gov/odf/Documents/forestbenefits/tree-declines-bigleaf-maple.pdf