imperialscum said:
Well he was still essentially calling all the shots in ESB. By the time he got the loan (and deal with Fox), creatively the most important part was already done with him having absolute power. Even after that he still seemed to be in complete control, considering he fired Kurtz (producer) in the middle of principal photography.

Kurtz went once most of his work was done and he had already contributed ideas that were to lead into ROTJ (albeit in a contractual obligation album realisation rather the four more sequel episodes sense that was on the cards at that point).
At no time during the production of ESB was Lucas actually secure and reports from that time paint a picture of a very worried and almost paranoid person.
He is less paranoid during the making of ROTJ but just drained by his private life and trying to run a very big company.
Come the PT anyone saying no to Lucas would probably end up in the trash compactor.