You wouldn’t need to use Grade 1 indicators in literary context if you are in uncontracted braille – unless you are giving the name of a minor chord in music notation. For example: a minor 6 chord in first inversion would be:
;VI#6
The lower case indicator is part of the music code symbol for the lower case roman numeral.
Yes – use the UEB sharp, flat, natural signs in literary context. If you are in music context, use the music symbol.
I think your transcription of question 13 looks fine. But I would use the special right hand sign that indicates intervals are to be read upward:
.>>
And put a blank line between parallels.
Hope that helps!