You're welcome. Wish I could've written more, but I have a physics lab I am *still* behind on. They keep messing with my weekends. There is this gold 2-way stretch lycra stuff that I love that I think you should use for the gold in the bodysuit and the triangle appliques (all the gold stuff on the costume). I found mine at Joann's, but it has kind of a diamond texture to it, so I don't know if that would be okay or not. It didn't show too much on my sailor scout, but if you want another way of getting gold lycra, there is always Lycra House.
http://www.lycrahouse.com They have a couple different gold colors under the shiny lycra. Here is what the Joann's stuff looked like on a costume I made:
http://images.cosplay.com/showphoto.php?photo=220851 Sorry, but that is the best close-up I have. I'm thinking that it would probably show if somebody was like standing right next to you and staring at your costume, but the pattern wouldn't show up in pictures. It's only a seasonal fabric, though, at Joann's, so you'd have to make sure you were able to get enough first. Also, it stretches down the length of the fabric, so if you're trying to save money and cut the fabric the other direction, you can't stretch it. So because it'd be for a bodysuit I think you'd probably need to buy a bit more fabric than you'd think. On the plus side, though, the other bits of fabric left over from cutting out the long strips would probably be enough for one of the appliques.
For the neckline, I think you should make it so it's not attached originally, then add the trim, and then somewhere in the middle where you want it to pull together add a hook and eye or snap or something. Probably a hook and eye because the two sides don't really overlap too much. The thing that I'm still not sure on is how to get the seams in there and make the bodysuit be tight on you. What I'm thinking is maybe you could buy a white bodysuit online that is bigger than you need and then cut the lines into it and make the seam allowances however much it takes for it to be tight on you. Because bodysuits are really difficult to make. Anything that fitted is really a bear.
It's not love that makes the world go 'round; it's fanboys and fangirls.