I'm not an AFCAD designer, but I do like using extended built ones for airports such as KDFW/KIAH/KAUS etc. Typical operations at a busy airport such as KDFW have at least half the runways available at any one time, yet ATC in MSFS only has one for landing and maybe 2 for take-offs (1 IFR adn 1 VFR), even though there are 6 available.How would someone such as myself adjust the AFCAD file to allow multiple landing runways and multiple take-off runways?

Search the AFCAD files in the library for "crossing " which means that the AFCAD has short psuedo runways that makes FS9 think that all runways you want to be active are parallel. This is also called the "star" technique. This gets around the restriction in FS that all active runways must be nearly parallel.A number of these files is listed at www.projectai.com which I believe is where the participants that created this technique are located.You should also be aware of an FS9 limitation that became apparent that the properties (landing, take-off, or closed only) should be set the same at both ends.