Some answers to some questions
Aircraft captain in Chinook and Black Hawk - Left hand seat (most of the time)
Co-pilot in above aircraft - Right Hand Seat (most of the time)
WHY? The Aircraft Captain (PIC) is usually responsible for running the mission which is more difficult than flying the aircraft, therefore the job of flying is done primarily by the co-pilot - therefore the Captain's seat in those two aircraft is usually the left hand seat. (Also, in the Chinook, the left hand pilot usually does the start and shutdown procedures and steers using the steering control from the left seat leaving the other pilot to keep his/her hands and feet on the controls at all times.)
Flying pilot in right hand seat?
WHY? The very early helicopters had their controls fed straight to the mixing unit which was centrally located and there was seldom a second set of controls. Therefore having the collective in the centre of the aircraft meant less linkages - therefore flying pilot sits in right hand seat.
FW pilot in left hand seat?
WHY? I like the cavalry explanation the best. Also, the predominance of countries that drive LH drive cars has meant that that has carried over into aviation with the US leading the way. There are 18 countries around that world that still drive RH drive cars on the LH side of the road - mainly countries with a British colonial heritage with the notable exception of Japan.
(UK, Ireland, Australia, New Zealand, Papua New Guinea, Fiji, Japan, etc, etc)
The reason for this has been put down to horse and carts and whips etc... and also Roman legions marching on one side of the road in Britain and on the other side of the road on the continent. It's also put down to Napoleon's conquest of Europe.