Testers enamel tricky to thin? Not really if you use the right thinner. I use Testors brand thinner when using enamels. I'm not sure why you say it's tricky to thin to proper ratio.
I also airbrush using MM acrylics and never had issues of paint gumming up with an airbrush. I use Testors Universal acrylic thinner for that. ZERO issues using MM acrypics.
Testros Aztecs? I'd steer away from the cheap stuff Testors puts out. I won't even use their brand airbrush.
One thing about using Alclad is wearing a breathing asperator is a must since Alclad is a lacquer. It's also a hotter paint to use as well. Good stuff indeed except don't use Alclad's brand gloss black primer. Use plain old Gloss black enamel instead.
While your observations is good for beginners starting out, there are a lot of members here that have used paint you've listed with zero issues. I'm surprised you haven't used Tamiya acrylics. They are awesome paint to use with an airbrush.
I myself use a wide range of paint brands: MM enamels and acrylics, Vallejo, Tamiya, Gunze/Mr. Color, Aeromaster, Pollyscale/Floquil, Akan, Tamiya, Badger, Humbrol, even the Testors small bottles of enamel paints. Every single brand is a different animal in how to thin them correctly for airbrush use. The key is use the brand thinner to the paint.