One or two ideas for centrepieces, don't worry about telling me you hate them, I think that's part of the process of figuring out your style!
- You know when people stack champagne glasses and have a sort of champagne tower? Well i was thinking you could do a very small version of this with maybe 10 stacked glasses and instead of champagne having cascading white flowers. You could do this extremely cheaply with baby's breath and one or two roses or peonies. I mean like this, but smaller and with flowers: https://www.luuux.com/design/champagne-fountain-hit-or-miss
-A chessboard with pieces on it (white for the bride, black for the groom) with little pieces of paper in the top (I have chess pieces with slits cut in to the top already as we're having them as place settings) and have a fact about the bride or groom on each one. Fun conversation starter for guests. Plus you could have a couple of vases too, to make it properly weddingy.
-Simply candles and flowers. I know you're not allowed candles, but they don't have to be lit! they'd look beautiful just being there. Or use candle sticks as bud vases and have cascading flowers, and then put white roses in silver vases.
https://i1224.photobucket.com/albums/ee367/tomcantgetitup/6a0120a65f64b9970c017d3f6df046970c_zps0c487c8b.jpg
-An old camera with old black and white family photos in silver frames arranged with flowers. Actually it would work with or without a camera. You could also have old movie posters if you prefer (there's something about monochrome colour schemes that make me think of film noir).
https://i1224.photobucket.com/albums/ee367/tomcantgetitup/8a37a39e72c9525a20fa5019ea1f2416_zpsf13a74a9.jpg
-Small vintage cosmetic mirrors. They just look amazing. Surround with flowers and unlit candles, or put on a silver tray. For some reason, I think these would look good with a pack of cards (only spades and clubs) fanned out on a tray next to it/below to add black and white touches. You could add sweet facts about you and your OH to the cards, too, or you could invite guests to write words of wisdom on them for you.
https://i1224.photobucket.com/albums/ee367/tomcantgetitup/c60e9cfae1be37bb75f4fccbfd58494e_zps273ed823.jpg
-Silver trays with these types of boxes on. Fill the boxes with either white flower heads of with sweeties for guests.
https://i1224.photobucket.com/albums/ee367/tomcantgetitup/3fb5ee8d2b789c052c6b076cd8eb63ac_zps65db462f.jpg
-Silver wine goblets with antique style jewels draped over them. This would look amazing next to a tall glass vase of white roses.
https://i1224.photobucket.com/albums/ee367/tomcantgetitup/324a879d0800ebd6f5002fb1c7c59226_zpsc05c346c.jpg
-I actually got inspiration from this restaurant name for this, but I was thinking you could make small reproduction road signs (white letters, black background, square-ish shape) in about A4 size with important street names such as the street you grew up on etc and have them propped up in the middle of the table. These could be table names, but I think it would make a really unusual centrepiece, and would look good decorated with flowers.
https://i1224.photobucket.com/albums/ee367/tomcantgetitup/2a976703e69f2cf8e4a3a1e3596be772_zps3643e8bd.jpg
-Cake stands with black and white macaroons on for guests, and white flowers around the base.
https://i1224.photobucket.com/albums/ee367/tomcantgetitup/c76b5b823c5b8200d05e656a44bfb5ba_zpsdd565723.jpg
-Silver and glass wine goblets filled with flower heads and/or sweets. You could even put them on each place setting and have the sweets as favours. You could take this further and position them in a cluster in the centre but also have silver bowls filled with black and white sweets (Hersheys springs to mind).
https://i1224.photobucket.com/albums/ee367/tomcantgetitup/99eb96d79411471905a8f08a51fa258c_zps3fcecc29.jpg
https://i1224.photobucket.com/albums/ee367/tomcantgetitup/ScreenShot2013-04-14at000520_zps0ae7a6db.png
I think that's all I can think of for now. I read on your blog you were thinking about feathers so I'll give that idea loads of thought too!