Layer styles are an incredibly underrated feature, IMO.

I actually built a small business around them: http://photoshoplayerstyles.com/

Nope. Layer styles were pretty much designed for doing exactly that.

Don't underestimate the value of layer styles. In fact I would say that for most UI design 80% of the "visual style" can be achieved via layer styles.

Just make sure to Name and Group your layers, otherwise you can end up with 100s of layers named Layer N with undecipherable thumbnails. Also it's nice to save your most commonly used layer styles to swatches.