The general rule of thumb for embroidery and screen printing is use as few colours as possible, and try and avoid gradients of colour - stick to solids.
Having said that, you can pretty much print anything on anything these days, so its less of a concern than it used to be.
The current 1st rank of mine would probably not work in embroidery to be honest, but I can't see it being a problem on T-shirts.
In terms of fonts, the two I have used in this design are called Estilo and Granjon Small Caps.
Currently the colours are in CMYK which is the standard for 4 colour process printing.