I am preparing my models for Substance Painter, but I don't quite understand how their tutorial prepare their models. - Q1: While I know how to assign a material to faces, I don't know how to verify what materials a face has in Maya? - Q2: They seem to be able to select faces by material, did they achieve that by splitting…
In the Hypershade, you can right click on a material and get a selection of everything it's assigned to. This button grabs all materials on an object (but not face selection). You may want to check out Material Manager, super super handy script by Bartalon, it auto highlights materials in the list based on selection.