I've always called those a "boat motor". I guess I got that from the food channel on cable. We have one, and yes, it is very useful for quite a few cooking needs.
When cooking sauces and stews, I favor making a roux. If I need a clear sauce/gravy, it's corn starch. I've looked for xanthan gum in the local markets, but since there is very little call for it no one carries it.