First off, I absolutely think that black is fine to wear to a wedding. There are weddings I go to where I feel like almost every single woman is wearing black. Plus, with all that lace on your dress, yours is particularly festive.
As for the necklace, it is always difficult to tell when it isn't being worn, but it looks like that will go well. I understand your concern about not wanting to overpower with jewelry since the dress has that lace overlay, but I think the pearls are pretty simple and won't take away from the dress. Alternatively, I might forgo a necklace completely, since the neckline is higher, and instead go for a stack of bracelets (do you have any bangles) and/or a pair of bold chandelier earrings. Personally, I would probably go that route, and since I often make my own jewelry I would probably use a brightly colored gemstone for my earrings--peridot or garnet or dark pink tourmaline.
I would also wear brightly colored shoes, but I love bright colors with black. I know that's not everyone's cup of tea.