It is *very* understandable that you have more questions, especially after shifting from UEB with Nemeth!
Some responses to your questions:
You *should* use 5-5 for directions. There should *not* be a blank line between a cell-5 heading and directions.
The fourth paragraph of #3. General format in BANA's Provisional Guidance for Transcribing Mathematics in UEB says, "For directions preceding itemized materials, use margins 5-5. If there are additional paragraphs, use margins 7-5. For directive sentences that precede material that is not itemized use margins 3-1." Beyond the GTM and the BANA guidance, our formatting guide for UEB Math/Science transcriptions is Braille Formats 2016, whose Example 10-2 shows NO blank line between a cell-5 heading and directions that follow.
For Duxbury, if you insert the DBT code "skn" as the first thing within the Directions paragraph style, that should get rid of (or "nullify") the skip line you're getting between the heading and the directions. Please let me know if you have questions about how to insert a DBT code.
As you said, yes, definitely you need both the parentheses (which appear in print) and the general fraction indicators (which indicate print arrangement).
So, the braille I would use for the print you describe is:
#e"<(y"-#b./#d)"> "7 ;m
There will be! A thoughtful group in Canada is working on a UEB Math/Science version of BANA's UEB-with-Nemeth Graphing Calculator Guidelines.
I appreciate that's not helpful to you right now. For what it's worth, my understanding is that the philosophy of the UEB-with-Nemeth Graphing Calculator Guidelines is being followed for the UEB Math/Science version, and most of the changes are simply to use UEB symbols instead of any Nemeth Code symbols.
Thank you for the questions! I look forward to more!