But what if the captain is being premature with the checklist ? Can an FO tell such to a captain without upsetting him ?
John the Captain can't be premature with the checklist as things happen when he wants them too. It's a not so subtle hint that the First Officer should be ready by now. Remember it's his responsibility and if you push late because you haven't done the checks in time it is the Captain who has to justify it.
Conversely if you start pushing the Captain because you think things should be happening now then I would suggest that you are stepping out of line. Of course if it's
obvious that he's forgotten something then you should point it out.
As far as having your feet on the rudder pedals. Our manual states that PNF should have his hands and feet on or near the controls at critical stages of flight but must ensure that he does not interfere with PF's inputs on the controls.
And the Captain has the authority to deviate from any SOP should he consider it necessary. Of course good CRM dictates that he notifies you what he's going to do and why, but he doesn't have to justify it to the F/O. However, if the F/O wishes to deviate from the SOP then he must justify it to the Captain who then has the final say.