You say use world of ai, but I don't quite fully understand what that does? Does that just make certain airports have certain airlines there and in the area or will the airlines now become the AI traffic all over the world with much more activity? And can you have multiple or just one?
World of ai provides realistic traffic within the limits of fs. All flights are based on real-world flightplans and use accurate aircraft (although some airline packages are a bit dated). If you download the American Airlines package, for example, you'll see the AA ai aircraft flying routes the carrier serves in the real world.
You can download as many or as few airline packages as you like. Obviously, the more airlines you download, the more realistic and immersive, but it is entirely up to you.
Hope that clarifies it a bit. If you have any further questions, feel free to ask. It might take a bit of time to install the packages you want, but the results are well worth it in my opinion.
