MB....I think the roll outs tend to have more flour..??? There are probably tons of different recipes. I like my soft. Some sugar cookies are hard. Just like gingerbread cookies...I like mine soft but my husband likes more of the ginger "snap" texture.
I worked at a "production" bakery...and they knew a lot about other bakeries. "Most" production bakeries do not bake from scratch. They are about volume and "production". You would be surprised who uses the bulk mix. No biggie to me.
No, no, no on the icing with mousse. You will have a 4th disaster.
To fill make a butter cream damn first...THEN fill with mousse. Make sure your filling isn't higher than your damn.
Ice with either ganache or butter cream.