It's tough to shop as a female with a bigger body. That dress wouldn't be so bad on a bigger girl because it's not as defining as some others. Now again every shape is different and every preference is different also, so no opinion is fact. A lot of shirts and dresses now are being made with higher or no waists to compliment a variety of body shapes. In my opinion, your link is fashionable and would look good, but as a few others say, the color may need modification, regardless of size.
I think it'll look great. Any type of fashion will look great - whether the person is small or big - as long as you have the right size. Nice fitted outfits enhance a person's body - I have seen girls go for one size smaller when they are 2 size bigger OR some girls go for one size too big when they are 3 size smaller. You know what I mean? It doesn't label you with anything - the outfit then just seems to be awkward if you don't coordinate the size with your own body type. Just make sure you get the right size that goes with your body and you'll look great.
hm.i think it depends. If you top half is significantly bigger than your legs this might not flatter you, but if that's not the case I think it would look really cute. Be sure to wear dark colored leggings like black or something
It depends on the size of the girl. It's also very important that the tunic isn't TOO baggy or TOO tight. A waist belt could help define your waist. Really couldn't say if it would work for sure unless you saw the actual person in the actual tunic.