Although transportation for 21 years for stealing a hat seems a little extreme. Although I doubt it would be his first offence.

William was a chimmney sweep in Ruardean, and had been caught and sentenced for stealing apples and potatoes on two occasions, The robbery "felony" was the third strike and out- very literally.

a marriage for Barzillai and Elizabeth. Which parish records would you suggest I try to find the marriage in?

I'd start in Mitcheldean, then Ruardean, then Lea, then Newland/Flaxley etc