4.2.5 explains that if a modifier (diacritic marking) applies to more than one letter, you enclose the letters in braille grouping indicators. These are NOT parentheses. They are the base grouping indicators which are dots 126, 345. The parentheses will have the dot 5 in front of the base grouping indicator. They are similar...but not the same; so both can be used without problem.
There is no diacritic hyphen in UEB. Follow print for whatever is used between syllables. If it's a space, use a space. If it's a hyphen, use a hyphen. If it's the mid-line dot, use the 456, 256 (bullet) symbol. You can also use contractions in diacritics unless there is a modifier on one of the letters in the contraction.