ProRes is 10-bit not 8-bit, there is no good reason to use (HQ) for standard video codecs, and several reasons not to, use LT if you want a chance at smoother playback. You can playback ProRes from any system if you get the player codec from Apple, FCP does not need to be installed to play it back.
But do yourself a favor and encode the movie to H264, your can get great quality and reduce the playback concerns.