For duplicate actresses, you can select both of them, right-click, and merge them into the same entry. This will make sure all the movie files are updated as well if that option is enabled in Settings. From there, you can properly capitalize the name if you want.
I'm not sure why I didn't use a case-insensitive compare for actress names. Maybe I just assumed it wouldn't typically be an issues.
Regarding files such as 1.mp4, etc... JavLuv won't typically make an entry for files that don't contain a proper ID code, unless you specifically enable this behavior in setting. And then, you'll need to provide all metadata yourself.