I can't speak from experience, but it should do pretty well. Placement and mode will be important to play with until you find the sound you're looking for. I'd recommend getting a stand to mount it on so it isn't actually sitting on the piano, but even that might be optional depending on the quality you're aiming for and the style of music.
Hi Andrea! This microphone has magnificent qualities as far as voice recording is concerned, so I would say "yes" if that were your purpose. As far as a live deal, I'm not sure, because I have not used it for that. With that being said, this mike has near zero latency, so I'm sure with the proper mixing board, this would be easy to balance with other feeds. The ability for this mike to alter the direction for which it 'listens' for sounds is sexy from the desk-recording point-of-view I use it for, but in the context of this question, makes me wonder if it is 'making up' for what other more expensive "professional" microphones might offer that are intended for performance. All in all, I would not be scared to try it. Sorry for the rambling, and hope this helps. Happy Holidays!
Just like any other product you purchase, this should come with an invoice. You usually find it inside the box along with the product or more often in a small plastic bag on the outside of the box next to the courier stickers.
It would really depend on the software. I don't think the holdup would be the Yeti. It would be finding a program that can accept multiple audio inputs. Most audio software (like Audacity) wants you to choose one incoming source.