Tom, Who did the the guitar for the end part? Was it you?
I also thought at first that Bob was holding his middle fingers up at the end but then I realised that he is holding his hands up against his head (duh me!!) but it was all really good, you seem to be quite hard on your yourself saying stuff about your work looking cartoony and fake, how long have you been doing this? Surely you can associate any learning curve like this to the guitar, it doesnt all come at once and you sometimes dont even notice your own improvement because you have been there for all the mistakes and hard graft.
Coming from someone who understands how CGI is created but has never actually used any 3d editing software, I thought it was really good, little things like Bob moving his head to take in the audience at the begining and the bow, it was good stuff mate, if you enjoy what you are doing and your always learning new stuff, then you will do just fine.
Stick with it.
Phil.