I think the issue is going to come down to how it's attached. Our towel rack has a plate that is screwed into the wall that the towel rack slides on to. Pulls for drawers or cabinets generally have screws. If that isn't an issue with the towel rack, I don't know why you couldn't use it as a pull. After all, who's going to know if you don't tell them?

If you look at the installation instructions you'll see that there are mounts that are installed into the wall, and the bar supports are slipped onto the mounts. You would need to know the depth of the mounts to make sure they aren't deeper than the thickness of your doors and drawfronts.

Why not go stainless and then Lee Valley has these pulls in a huge number of sizes. Remember towels bars stick out a lot further than door handles.