Uh. I totally forgot everything about statistics and probabilities (and I'm too lazy to remember those, so I won't check numbers 4 and 6), but I think the core idea how it works is that Bob's option just has lower chances. Say, we toss a coin up to 3 times.

Possible outcomes are: TTT, TTH, THT, THH, HTT, HTH, HHT, HHH

Alice successes are: HT, THT, and HHT, but Bob has less options: HH and THH. That's why he needs more tosses on average.