Oh Well, Oh Well

does it make anyone else uncomfortable that they changed her entire race because she went out with Ron in their sixth year

Umm, no. They did not change her entire race simply because she dated Ron. Actually think about it. Up until the sixth book, she was a background character that was only ever mentioned in passing, so she wasn’t given a physical description. Then in the sixth book, Lavender was finally described, as having ‘pale skin and dirty blonde hair’. Well, the first few Harry Potter movies came out before the Half-Blood Prince book did, so the casting directors did what they wanted with the character. 

AUDIENCE MEMBER: I was just wondering about the creative decision to bring Moriarty back. I’m thrilled, but you were very adamant he wasn’t coming back. MOFFAT: …Because I’ve always given this grand commitment to telling the truth! [laughter]. You don’t know what’s going on there. You don’t know what’s going on there. We know what’s going on there, but we’re not telling you…for bloody ages. …It must be hell watching this show.

Traversing the galaxy for intergalactic travels to Pigfarts!