After I have watched an episode on via my Roku I would like to delete it from my PC via my Roku. We already know that the Playon on Roku can communicate back to the PC because it has the ability to request that the PC record an episode. So I see no technical reason why a delete request cannot be made from the Roku screen. The Playon app on the PC already has the delete ability.
Delete button on Roku Playon Screen