I sure you have all the data you need on Robert & John Cook. They were indeed father & son and both millers at Oakley. Robert appears to have found himself in financial difficulties in 1810 and John likewise in 1820-21. You should be able to find some refs in the London Gazette's online archive). Robert died in 1823 and the obit mentions he was miller at Oakley and then, interestingly, at Dickleburgh (Bury & Norwich Post, 1823/02/19).
The connection with Edward Bullock seems to be more that Edward was a significant creditor (as Robert assigned all his assets over to Edward).
Another daughter of Robert, Matilda, married a John Clark of Newmarket in December 1808.
My own interested is in the milling side so if any one can point to any evidence of when Robert Cook started milling at Oakley (or any milling data pre-1810) I'd be very grateful!!!
Cheers,
Windy Miller