On the headings--Collumn headings that follow a cell-5 heading work just as shown in Example 4-12. Normally, there is no blank line after a cell-5 heading, which is why there is no blank line separating a cell-5 heading from a cell-7 heading that follows it. But a blank line is added to separate the cell-5 heading from from columns so that it is clear that the cell-5 heading refers to all the columns and not just one of them. This is stated in that Formats section, in the example and in the Formats Appendix C Blank Lines. Cell-7 headings work the same way.
On UEB: 1. Yes, contractions are used with diacritics unless there is a modified letter involved that is part of a contraction 2. The diacritic hyphen is not a valid UEB symbol. Use a regular UEB hyphen if there is a hyphen in print. 3. In UEB, spaces are left as spaces, even in diacritics, just as the example shows.
There has not been any announcement from BANA or ICEB regarding a future UEB manual. There is a BANA task force working on updating Formats to be consistent with UEB and therefore some of the above provisions may change, particularly with regard to the use of hyphen within diacritics. But this is not approved by BANA at this time, so the current UEB usages apply to formatting.
I consulted with Cindi Laurent who is the chair of the NBA and BANA Formats committees.