Hi Vic,There is often significant differences between the manufacturers limitations and the airlines. For example, at United we subtract ten knots from all the flap extention speeds to increase flap track and actuator life (We put out flaps 1 at 230 kts intead of 240 kts on the 767). In reality, we don't have access to the manufacturers limitations, we have a Flight Manual for our particular aircraft that's published by United and approved by the FAA, so we often don't know whether a limit is FAA, United or the manufacturers.
As far as getting a visit up-front while in flight, there are only two legal ways to do it. One is to work for an airline, the other is to be good friends with the captain and have a very flexible schedule. It's only legal for a non-airline pilot to ride in the cockpit on a ferry flight. In other words when there are no passengers on board. Ferry flights are generally only planned a short time in advance, hence the need for a flexible schedule. I've been trying for years to bet one of my brothers up there, but the timing has never worked out!
Mark