In reality, an airline pilot cannot fly any flight he/she wants. The flights are being "assigned" to the pilot by the airline dispatch center based on his (or her) capabilities, knowledge about the aircraft, etc.
In phpvms, any pilot can bid a flight. Bidding the flight is like booking a flight. It means that he/she "says" that he/she is going to fly this specific flight. Of course, if he/she don't want to fly this flight, he/she can just remove from his/her bids. Also, bidding the flight gives your pilots the chance to access their boarding pass.
As for the other questions, personally i have not understood what do you mean exactly and what kind of information do you want.