The trick with the signature line is to only ever post one photo file on it. Combine all your badges into one photo file, then start over with your signature line. Delete everything, save it, then add your (short bit of) text and the single photo file and save it again. Any more than that quickley crosses the line, seems like.
Since I don't know if you are counting the characters in the HTML as already saved, or as you are trying to save it, I can't say what's up with that. It doesn't matter, though. Perform the above process, and you're good.
Flight deck: Hasegawa 1:48 P-40E; Tamiya 1:48 A6M2 N Type 2 ('Rufe')
Elevators: Airfix 1:72 Grumman Duck; AM 1:72 F-4J