Even coatings are not required since one exposes downward through the gelatin -- how much unexposed gelatin is under the exposed gelatin does not matter (as long as there is some unexposed gelatin).
I tried using .007" film stock a long time ago. I had trouble getting good contact in the printing frame -- the support was too stiff. But more pressure (or a vacuum frame) might allow it to work.
Coat as large of a tisse as you can -- then once it is dry, cut it down to the sizes you need.
Your coating method #2 is the one I use -- I like getting my finger into the black glop!
If you see a polar bear in Poland, he'll probably have some Yupo in his backpack.