Asking where something is
Yeah you've pretty much got it.

请问 is just a good, polite, way of giving the other person a heads up that you want to get some information out of them.

It's not necessarily demanding to drop the 请问, it all depends on your tone of voice.

If you're looking for more demanding way just drop the 在哪里 altogether and add a 呢 on the end while being overbearing. 呢 can also be fine by itself but again, it mostly depends on your tone of voice.