How is it decided which pilot will be the pilot flying that particular flight considering there is every possibility that a Captain and FO have previously flown on different flights. Is this something that is negotiated between the two pilots, or is it something which is arranged by scheduling.
We use lower cross wind limits for the FOs which precludes them operating sometimes, and they also never do the low vis (auto lands). Beyond that, it's totally at the whim of the captain. Scheduling sometimes ask for a sector for a bloke whose recency is running out, but they can only ask. Mostly it's turn about. I've known of captains who never/rarely give a sector away.
Also how does the load split between the pilot flying and the pilot not flying. Does the switches which each pilot would normally set remain the same.
In the Boeing, the FO always did most of the coughpit preflight, with the captain just doing what was on his side, and then checking what had been loaded into the FMC. In the Airbus, most of the coughpit is set up by the pilot flying. Once in the air, autopilot settings are changed by the pilot flying only, whilst most FMC work is done by the non flying. Radio is done by PNF (pilot not flying).
An example would be the APU start switch in the B747 is directly over the Captain, assuming this is a switch which the Captain would normally operate, would that remain the same regardless of if the Captain is the PF or the PNF? If the FO is the PF, does the FO give "instruction" (sorry, couldn't think of a better word) to the Captain asking for certain actions to be done? Or are there switches which are only really to be operated by the PF?
APU start after landing is done by the PNF. Before the flight, generally by the FO. The pilot flying, if hand flying, will call for MCP (mode control panel) changes otherwise he alone makes them. Configuration changes are made by the PNF as called for by the PF. So, basically, the only things that are always done by the Capt or FO relate to switches associated with their displays. Pretty much everything else swaps from side to side depending upon who is flying.
Also how much can the PNF do independent of the PF, for example say the FO is the PF, can the Captain (PNF) turn on fuel pumps without specifically been asked by the FO (PF) because it needed to be done, or must the PNF await all instructions from the PF. (Obviously regardless of who the PNF and PF is, if a system mode was changed, there would be a call out stating it has been done to the other pilot)
Items such as fuel pumps are covered in the preflight checklist and are done exactly in order, by the specified pilot. About the only things that are done by first bloke into the seats is to initiate the download of the flight plan, and to realign the inertial navs. Both occur in the checklist but they take time and it's better to have them done asap.
it may have been 5 in front of me, I know the circuit was full 
totally engrossing!!
