Aw, well Fleur will surely talk to her once she does even if she's only a Weasley by marriage. He can be a friend of Bill's if you like. If not they can just be friendly.
Prob not. Hermione is one of those you either like or don't like I think. I don't think there is many shades of gray there. They do probably know of each other. She needs people to set her in her place. Bug away she'll snark back.