The word street is a common noun. It is a proper noun only when it names a specific street such as Main Street or the name of something or someone like Farley's Street Market or Della Street.
Yes, Watts Street is a noun, a proper noun because it is the name of a specific street. Proper nouns are always capitalized.
Yes
Idk look it up t.t
well it wound be like lets say black foot street because it is a street