I think your handling routine is about right. You could probably go with handling every other day here & there and then wait 3 days in between. I think 20 minutes is about right, too.
To be perfectly honest, it's not so much "how long or often" you handle it, but "HOW" you handle it during those times.
First priority is to gain their trust. No sudden movements, avoid hectic scenarios/environments, keeping a hand or two near it's face for the first few months or so so it can see & learn that a hand is not a threat, etc...
Basically, you have to trust it before you can get it to trust you. Takes some guts with biters sometimes. Handle with confidence but respect. The snake will detect it and usually react accordingly.
Some Burmese pythons are life-long hissers. I've got a 12ft 4yr old that's hissed all her life but has never struck once. She's very gentle and anyone can handle her. Sometimes it seems as if her hissing is more like she's whistling a happy tune. Even though I trust her, because I'm not 100% sure why she whisltes, I still watch her. I can do anything I want to with her and her hissing tone never changes. She doesn't hiss continuously, but most of the time.
Hissing doesn't mean it's a mean snake, mean snakes bite, strike. By most standards hissing is considered to indicate that they're unsure of something, or possibly displeased with something.
Hope this helps!
HH
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Due to political correctness run amuck,
this ol' hillbilly is now referred to as an:
Appalachian American

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