Thanks for sharing your experience awakening one. I really feel that this sharing will help us all. I picked up several ideas from your post.
Fist is that I too have notice that subtle changes in the posture and movements can greatly change the feel. Watching Master Lin is great for seeing these subtlies. Two of mind are: the leading with the elbos in and a slight rotation of the hands at the top and bottom of Moving Yin and Yang. I'll watch the video again for the hand action in Joining Yin and Yang.
I do my exercises in silence as opposed to watching on TV because I don't want to wake the rest of my family... anymore than I already do. I also spend a lot of time on the first for exercise. Sometimes not even getting to the last two. Usually only doing one of them.
I don't go into the emptiness except in the first exercise. I treat it like the tangerine technique in PhotoReading. I go through that door and leave it behind. I've been spending quite a long time in this exercise lately. Trying to fully feel the emptiness, I think it is getting stronger for me.
I still have a significant amounts of mental chatter while doing the exercises. I deal with it differently, I think I may try and going through that emptiness door. You're experience seems so good.
My best experiences seem to be when I can completely emmerse myself in the exercise. Visualizing and feeling.
I find that I'm still constantly correcting myself. I find that taking it as a gentle reminder and smiling at the helpful information, and not expecting myself to have totally mastery is when I things go best.
As for the closing. Of course use it. 
Actually I'll thank for reminding of why I started using it. It FEELS good to do it. Also I've started using a different message, and I've notice that lately my connection to that feeling is not a present with me, so I may flip back and forth. My new message is best when I have the feeling present.
You are perfection,
Iam2 
P.S. I'm feeling it, thanks to your post.
