Excellent set of tutorials. I like that you've set up a section for these. They also highlight the strength of legacy versions with skills that can be used in any FS version.
I think it might be helpful to enhance the professional credibility for the tutorial and FlightSim, if Bill, Nels, and other tutorial writers would add their FAA certificates to their profiles (ATP, CFI, MEI, CFII, GI, etc.), and maybe ttl flight time and types of flying (Corporate, Military, Air Carrier, etc).
Good tutorials, along with the availability of a wide range of downloads help to enhance the strength of FlightSim as THE go to site for sim pilots.