Non commercial products don't require to display the GameStudio logo. If you release and publish a commercial game with Pro edition you also are not forced to show the logo and have a option to change the engine startup window. Not really understand why someone wants to unconnect a game from GameStudio. Most commercial games created with GameStudio show the logo anyway. Guess as a thank you?

To have minimum connections to the engine. You need to write games in C++ using the acknex.dll. Not to hide anything, but to accomplish things that are not possible with default features or perhaps in the case one just don't like script language.