The top hand should more or less stay completely still.
I disagree. The top hand should be uninvolved in the mechanics of the move, but it should be in motion.
First, after you cut the card to the middle, take your top hand away and let the spectators see the deck laying in your somewhat open hand.. This is an "open" move that gives the spectators the sense that you have completed returning the card to the middle of the deck and nothing else has happened (which it hasn't!). As long as you are aware of your angles, you can keep your pinkie holding what it is holding.
Then, bring the top hand back to square the deck (think running thumb and fingers along the short side of the deck). As your hand is in motion, it provides cover for the move. Of course, when you do this, your attention should be elsewhere and it should look like you are just squaring the deck out of habit. When you are done the move, keep deck in mechanics grip and move the top hand away.
The synchronization of the move with the squaring motion makes the pass more smooth because you don't have to do the move quickly because you have cover. The cover is both the hand passing over the deck by squaring it and the larger motion of bringing the hand back to the deck. Remember, the larger motion covers the smaller motion.
You can provide additional cover by directing your attention with your eyes and your body (think shifting your head and shoulders). So when you put the card in and pull your hand away, look to and talk to a person on your right. As you bring your hand back to square the deck, shift your attention to someone on your left. You to start talking as you shift your attention (and bring your hand around) and do the move mid-sentence. After the move, you can direct your attention to the middle of the audience.
is there any place to see your pass,
So I don't use the pass to control a single card -- there are a lot better methods.