I am not flaming the OP but how is what they want to do any different then using Disney Transportation buses from WDW Resorts you are not staying at? I know that since they are owned by WDW they are same expect for the themes of the Resorts, where as the Hotels on International Drive are owned by different companies. What I am saying is I am sure that happens everyday at WDW and no one says anything about that and even though WDW says guests maybe asked to show their KTTW cards before using Disney Transportation, 99.9% they never check so anyone can ride Disney buses without staying at a Resort they are visiting. So unless these Hotels on International Drive check to make sure the only guests who ride them are guests staying there, then the OP can not do that. However if the OP does do this and get away with it, then maybe the Hotels on International Drive should make sure only guests who stay there can use the Transportation buses to Disney.
Please note I am not telling the OP to do this, I am speaking from a technicall point of view and saying what might happen.