I dont think a bonus gallery would cause any problems getting listed, but why give more away than you need to? I'd use that content to make another site. I guess I dont understand what people are calling a teaser gallery, isnt that what all your galleries on a free site are suppose to be?
Again maybe you are on to something and I don't see it
If you really think are are on to something run with it, but I personally dont see the point.