Mooro, you can pretty much forget trying to brush paint Tamiya Acrylics, stick to your enamels for that. As far as spraying them, they work very well. At first try thinning with Tamiya thinner at 50/50 and about 15 to 20 PSI pressure and then experiment from there to find you own preferences, but those guidelines should get you off to a good start. As far as cleaning your airbrush, just use some Windex and water to clean up. Beats using Turps and thinners I reckon. For small details, I like using the Citadel paints, they work really well with a paintbrush, clean up with water and are non-toxic. Hope this helps you mate.
Cheers...Snowy.