I agree, Obadiah certainly seems to have led a "different" life. "Familysearch" Cheshire records have workhouse admissions & sunday school records for Obadiah, which I guess you've explored.
I learnt he can read & write, his occupation is listed as shoemaker, so he's educated, & should be employable. Why, when, for whatever reason, he returns to Cheshire after serving his sentence in NSW, does he end up in the workhouse about 12 times (from admission records) between 1861 - 1870? Is there more than one Obadiah Bann? Baptism records say his Mum is Nancy BAND and no Dad is recorded, Maybe, Nancy married / lived with with Mr Tunnicliffe - hence Obadiah's surname choice.
Interesting that his Grandmother left a Will, and more interesting that her wayward grandson is mentioned.
Oh, so many possibilities! Thank you, I'm enjoying "playing with" your distant ancestor.
Happy hunting, Valsgirl (Brisbane, Australia)