To me the rules sound generally common sense and reasonably natural extension of basic SB rules.
As for the template, I think that shipbucket logo in the lower-right corner should be always present, and personally I'd suggest to locate the buildings not on the bottom edge of template (like You did with skyscraper), but with some margin (as is the case with "main types" of drawings here), just with some black "ground line".
I have edited the drawing so that it is 20 pixels above the edge, with the Shipbucket URL at the same height as the black ground line. I will upload the edited drawing, and it will serve as the first example. Thank you for your feedback.
EDIT:
Here it is!