Since the question is specific to United, I'm going to move it to the
United Airlines forum.
Regarding the point above about transferring United miles to hotel programs, it is no longer possible to do so directly. (United --> Hilton used to be 1:2 but that was shut down earlier this year.)
You could, of course, still transfer United miles to Diners Club points (provided you have a Diners Club credit card) and redeem Diners points for hotel stays or points.
Regards,
Gary
aka gleff
MilesBuzz and Delta moderator