More answers about Player/Playback (AP) or:
Yes, it is possible to remove the "Articulate Powered Presentation" logo from the lower left-hand corner of the Articulate Player when using Presenter Professional.
This article refers only to the logo in the lower left-hand corner. If you're seeing an Articulate logo in the upper left-hand corner of your Player, then you simply need to add your own logo in Library and Options -> Logos, and/or select your custom logo from the Logos drop-down when you publish.
To remove the Articulate logo from the lower left-hand corner of the Player:
Note: Although it is possible to replace the logo in the upper left-hand corner with your own, the logo in the lower left-hand corner can only be removed.
Presenter '09 allows you to remove the logo and add your own.