I delivered at UCH in 2010 (vaginal delivery, induced) and this year in Jan (emergency c-sec). Both times, I didn't have a birth plan written down. The first time because my wants were very simple - husband being with me at delivery, as natural as possible, choice of epidural - so felt silly writing it down and also because my sense was that they would not accommodate extra requests. For the second, my baby was in breech so all plans were up in the air.
I think there is no harm in trying for the kind of birth you would ideally like to have but I would manage my expectations. So if I were you, I'd put down what I want and around 36 weeks, broach the subject with the midwife/doctor at your antenatal appointment and see if they accept it. However, even if they do, there is no guarantee that this is what will happen at your actual delivery. I think you have a shot at some things happening the way you'd like them if it's a vaginal delivery. If it's a c-section, I don't think they'd accept any of it.
Here's roughly what happens when you go into labour at UCH:
1. You go to the delivery suite to be admitted. You will meet a nurse for a brief interview to go over your medical records. If your appointments were at an MCH, you'll have an envelope of your history to give them. They will still ask you stuff about your blood tests etc. They generally ask if you want the father to be there, and take a copy of his ID card. This would be the point at which I would give refer to the birth plan and give them a copy again if not already in your file. For my second, I was advised that if I want an epidural (which didn't happen with my first) to clearly state that I want one at this point. They will then hook you up to a monitor to check fetal heart beat and a doctor may examine you to check dilation before they decide to admit you.
2. You then get taken up to the ward if you're in the early labour stage where you basically wait around. You are free to walk around, eat, etc.
3. When you're dilated to a certain degree or contractions coming at closely spaced intervals, they'll take you down to the delivery suite again and ask you to call your husband. At this point contractions would be pretty painful. You would be largely alone in the room with your husband and you might be able to play soft music (if you packed your own player, which runs on batteries) here to relax yourself.
4. When they think you're ready to give birth, they'll take you another room and yeah, the lights are pretty bright. I have a feeling getting them to dim the lights and play music here would be tricky. The fact is that even if you mentioned it on your birth plan, they might not bother and while focussing on pushing you might not want to fighting about this stuff, frankly you might not have the energy and mindspace to.
That's why I'm saying manage your expectations. Write a birth plan, discuss it, hope for the best, insist as much as you can without getting too stressed on the day itself and then just let go.