If I were a 20 year old with my 20 year old body I'd definitely wear #2.
I think #1 is pretty and I would wear that now but for you it would depend on how tall you are because a dress that falls bellow the knee will make you look short as it is.
Black for a wedding? I don't know...I would think any color but black would be more appropriate but then again I don't go to weddings.
No. 2
As for the gift part, i don't see anything wrong with requesting a gift card. If you already have everything for your home, why not a gift card for other necessities? Anything goes these days!
I would say number 2 but I think you said it was black, I'm aganist wearing the color back to a wedding.
Black for a wedding? I don't know...I would think any color but black would be more appropriate but then again I don't go to weddings.