How about if 'penalty' is simply use half OB?. Is exactly as if you create a style for a single weapon, you can use half OB for other similar weapons.
So, more DPs you pay (more ranks), more bonus difference you have for those maneuvers.
IMO is a bit excesive using like talent, so you have OR not have it, it is radical. In any case if you know combat you know a bit how to do those maneuvers in any manner, but are not skilled.
Let's think about an archer, you always can try to shoot longer, but if you are not skilled you do it worse.
As conclusion I think, as I said, that be skilled in something should not be free, as we can see it is not expensive (only 1 style point anyone), but you should be able to use them in a 'not skilled' form, if you are not skilled is not the same that you can't try it (are your muscles blocked for that movement? i.e. striking to your back).