I don’t want to start a war with any VFX creators, but I wouldn’t say it’s a field significant enough to be a separate role. They do, in the end, create art. It’s not your traditional art, but what else would you consider them? If a separate role was created, it would probably be called VFX Artist, which really doesn’t make much sense. It still contains the “Artist” part of it, therefore making it more of a sub-role.
I do agree with the Voice Actors. I haven’t seen that many of them here on Roblox (perhaps because of the audio system and the nature of most games), but when someone decides to become one, they can’t really identify themselves using a title. Composer is a very misleading term when referring to a voice actor. They don’t make music.
Project manager also seems like a good one.
Video editor isn’t really needed imo. Videos, unlike scripting, building, art, modeling, etc, aren’t a very important part of a game. If you wanted to hire someone to make a video for your game page, you could hire someone outside of Roblox or someone with that experience.