No reason not to. They shouldn’t need much though.
Not quite sure what you mean, but many people put an imirie shim on top of the top box, just below the inner cover, then put the patty on top of the top bars. That way the bees don’t have to leave the warmth of the main hive to get the food.
I have an 8-frame version of this, which would also work well:
You can certainly do that, and some commercial fondants come with a baking parchment wrapping, which you can leave on. The bees eat through and toss out the confetti.
That is fine too.
You could, but I wouldn’t give it to them until about January. You don’t want a population spike in midwinter, which the patty can stimulate. Then you would have tons of bees munching the food even faster and overcrowding the hive when they can’t get out to poop.