@mistersql 1. Depends on why/how often.
2. Generally I would avoid those, yes. Proficient screen reader users wil have ways to skip over them relatively simply, but not everyone has the tricks of the trade to do that which would mean every = is read out loud. Not a great experience. Dashes (-) tend to work a little better for this because a lot of screen reader punctuation schemes tend to not speak those by default, but it depends on a number of factors.
3. I'd say that is more subjective. For me personally I wouldn't really care either way, again because most screen readers don't read those by default. But if your tool is used in the context where a user has more punctuation enabled to follow code better those would add a lot of extra verbiage (left brace one right brace, left brace two right brace, left brace three right brace etc.)