I am living minutes from O'Connell street. I can say, not keen on Talbot street don't like walking on my own, although I do and have with no issues, however I have walked up and down O'Connell street & gardiner street from day on way to and from work every day, never felt or feel unsafe.
Not comfortable with Marlborough street, that's a street I walk long way to avoid. Couldn't tell you why, just not comfortable.