Ahhh the day has finally come!
I can feel your excitement! Congrats!
I could pretty much relate to everything you wrote in your first paragraph. Everything except the open bite, was true for me also.
It was very unprofessional of them to change the orthodontist on you in the heat of the moment, so to speak, without any forewarning. I hope at least the new guy was nice, or helpful, or both!
As for the braces, I'm pretty sure it's standard to have metal brackets on all the teeth that aren't the 'Social 6'. The teeth that show. So how do they look? I'm intrigued to see what the clear ones look like.
As for the chain, I would be mindful of staining, but there is no need to be anal about it. I was super worried about staining mine, but it was a waste of time. I have had my powerchain for just under two months and it has discoloured slightly but not enough for anyone but me to notice. Things that stain the most were satay kebabs (they turned 3 of my back ligs funny coloured, on the side that I chewed it) and curry based dishes. Bolognaise isn't as bad as I thought but chew at the back. Red wine, I'd steer clear of that. But tea, should be fine. Do you live near the ortho? Maybe you can ask him if you have major staining, if you can go in and get it changed.
It does suck when you have a million questions and you get there and forget them all, or don't have time to ask them. I'm hoping I get time to actually talk to my ortho properly next time.
Glad you're not in too much discomfort with your braces. Your front teeth will be tender soon for a while, and you wont be able to eat anything you have to bite into. But it will be worth it, that powerchain will close that space up mighty quickly!