I've been told that there is some built in diffeculties at different levels, like III air marchal is harder to play then II air marchal.
Can some one explain how it is, and how it works?

Nothing that I've seen. I've been experimenting with a brand new account (to relive the life of a noob), and it seems like the only difference is the plane speed (ugh) and bullet rate (or density or something). The first two planes are a real challenge, but so far all of them wheel around quickly, and actually are quite pleasant in a chasing battle. Top planes have to slow down to not overshoot, and we seem to turn the same. Long range seems all the same, and top ranks fall neither more easily nor less easily (hit boxes seem to be all the same as when I was higher ranked).

Oh one thing is that the lower point planes are WAY easier to land, and their takeoff speed seems lower, but even if that's just my brain imagining things, these planes are great in Capture Carrier... well once you get there, since it takes a couple hours just to get to a carrier!

One disadvantage to slower planes is that they don't jump off the start line when you hold brakes with throttle.

Tanks and chutes seem all the same, regardless of rank. At least with this sampling. I'll let you know when I make it to Air Marshal, sometime maybe in 2014.

Lt-Commander II Manfred

Can't climb as hard either. Noob planes do a nice power-on stall.