I always use WSS for towels and napkins so I imagine your product would be fine.
For T shirts, why not try on an old one, wear it and wash it and see what happens? I have always used a polymesh but why not have a go?

All three items require different stabilizers. You might be able to use it for napkins and other linens.

The reason you use an iron on for t-shirts is to stabilize the whole area to prevent stretching or distortion while embroidering. You still need WSS as a topper for towels and tearaway bits wash out.

Most of the embroidery machine books that come with machines pretty well cover the stabilizer questions.

Good chart:
http://www.diamondthreadworks.com/embroidery_chart.htm