why are you using the standard deviation for one trial with a sample of 100 trials? Don't you need to use the standard deviation for 100 trials?
The mean for 100 trials is the expected value for 100 trials. Since the EV for one trial is zero, so should the EV for 100 be. And the EV outcome of winning all 100 would be 200, not 2. I think you're considering the wrong sort of mean, otherwise I am.In the case of 100 wins the mean is 2 so it should be clear that your bounds were meaninglessly large.
Can you address what the results of my long form calculation at the end of the post would be? Would it be the same as the 95% confidence interval or something different entirely. If the latter, then confidence interval is definitely not the value that interests me.