Hi. Thank you for asking these important questions.
Regarding question 29, yes, a space must precede the open parenthesis. The 2007 update to Section 119.a of the Nemeth Code says this: "A space must be left after an unmodified function name or its abbreviation. If the function name or its abbreviation carries a superscript, subscript, modifier, or other braille indicator, the space must follow the superscript, subscript, termination of modifier, or other braille indicator."
Regarding questions 30 and 41, 3:4:5 is a ratio. It means that the side lengths are in the ratio of 3:4:5.