As far as him hissing when you go to pick him up, he should outgrow that as he gets older and realizes you are not going to hurt him (think about how big you look to him and hissing and striking are his only defense-be grateful he's not striking!!!)
Start hook training him now-a light tap on the head before you pull him out and he will learn that means he's being picked up.
Handle him often now, remember to leave him alone for a couple of days after feeding so he has time to digest. As he grows you will learn more and more about his personality. Always remember to have someone else with you when you handle him as he gets bigger. You can handle him a couple of times a week so he stays calm and reamins used to it.
One of the reasons burms can be picky eaters especially during the winters months is because that is breeding season and some males will not eat at all during this time whether they are with a female or not. Greens, albinos, granites, etc... they all do it.
Don't apologize for all the questions-thats what we're here for!!!