To be a rock star on the V4, you need to have the most skill points in the second category, the one represented with a *. Bandai's website recommends getting at least 80 skill points, but I have found you could get a job like rock star sometimes with as few as 40. I would aim for 50-60-70ish if possible, but if you get 80-90+, you will almost definitely get the job. Good luck!