Garage Band does not have Podcast creation option

Actually, you can't. The linked article specifies exactly that you can't:

to create your own original music compositions or audio projects. You may broadcast and/or distribute your own music compositions or audio projects that were created using the Audio Content, however, individual audio loops may not be commercially or otherwise distributed on a standalone basis, nor may they be repackaged in whole or in part as audio samples, sound effects or music beds."

(emphasis mine)

You can create as many songs as you want using all the sounds you have in the loops and sell the songs. But you will be packaging the sounds (or repackaging) as audio samples of your application which seems to be forbidden.

Also. If the keyboard is not faded. It might just be that you have the velocity turned down to zero. turn it up :). the velocity controls are right below the keys when you have the keyboard on musical typing mode