Auto-trace masks to shape layer?

Not sure what you are asking. Of course it may simply be necessary to have multiple comps and even more duplicate layers to achieve whatever effect you are after. That's just how it is. It's all an illusion. Things that look simple can consist of hundreds of layers and pre-comps sometimes and just in reverse sometimes an effect that looks complicated is the cheapest trick in the book with only a handful of layers. No need to get strung up on technical perfection or trying to be über-efficient with as few layers as possible. Just think this through properly and then structure your compositions accordingly.

Mylenium

The Stroke effect only works on masks. Trim Paths works on shape layers with stroke applied and no fill. If the shape has a fill and a stroke and Trim Paths it will generate some weirdness in the fill. 

If you need to use Roughen Edges on a layer with a mask and stroke, you first need to pre-compose the layer moving all attributes to the new comp, then apply Roughen Edges.  

What exactly are you trying to do? If it is what I think then all you have to do is pre-compose then apply Roughen Edges.

Check AEScripts.com. There's any number of mask/ shape path auxiliary scripts, including ones that copy&paste and convert layer types.

Mylenium