Answers to your questions!
1) The best way to beef up the shoulders, which is what I did onthe ZCWO body, definitely the body best suited to Bateman, is take fabric tape and tape a part of a cotton ball nice and even on the body under the shirt. if you do a clean and even job the tape and cotton will not be noticeable even with the jacket off.
2) Everything you said about Hannibal's body issues was completely correct
You might not want to go this route as it's a little pricey but here is my recipe.
Hot TOys slim upper half and regular narrow shoulder bottom half with the original iminime fatsuit on.