In Options / preferences / advanced / offers.sponsored_torrent_offer_enable set the value to false. Restart utorrent.
They may change this in the future so use the filter search for similar word that would disable the add.
„Please enter a computer name“ error may appear when the default playback device is changed to something other than it’s built-in player. A dull but effective solution is to type something completely random in the text boxes, then later disable the remote access setting.
I still remember the times when uTorrent was a very small and lightning fast torrent software, a simple .exe file. The increasingly bloated commercial add-filled check-box cluttered crap steadily drives me to the point that I will switch to some other client.