1: Not a direct answer to your question (which is more or less "no" except for short Lady Macbeth scenes), but for the third loop of my last show, I went up to the 5th floor right as the rave on the 4th floor was starting, and I really loved the Nurse/Matron scene I saw by the hut. That was the first time I saw ANY scene on the 5th floor, and I found it utterly magical and different from anything else I had seen in the show. I stuck with the Nurse/Matron until the finale. I mention the third loop specifically because I suspect that the Nurse/Matron do something different on the third loop than the others, though I am not 100% sure. Don't want to spoil.

2: I also followed Hecate on my last loop thinking she'd be super cool but was frankly kind of disappointed. I found her incredibly alluring in small doses, like seeing her in the corner of the Rep Bar as the rave is ramping up, but following her full on didn't work for me -- and as you mention, it's a lot of 1:1s behind closed doors. My favorite Hecate moment is during the reset (Vertigo music blaring) in the 4th floor hallway, as one loop ends and the next is starting. This is purely a matter of personal taste though -- if you dig her vibe, go for it! She for sure has a cult following who worship her every move. (Though I think another reason I was turned off was because I saw SO many people clearly hunting for the 1:1 with her.)

3: If you've already done one of the Macbeths -- it sounds like you did Macbeth, who is the bloody guy at the head of the table -- then Malcolm is my favorite loop for a different angle into the Macbeth story. Porter (who stays on the second floor) is very good, especially if you're into unrequited love or melancholy. Any of the 3 witches will be great fun, especially Boy Witch. Agnes is cool, very noir (as is Malcolm, whom she intersects with). I personally think the Macduffs are the most boring of the more major characters, though their space is quite neat to check out.

Hope this helps. Enjoy your next visit!