Elliot C. yeah in theory they shouldn't affect anything because when it shows up in this menu, it means that they are not being used in the project anywhere. So some of these were that first screen you saw when you duplicated the project, some of them are combo classes, etc. The only two I see that are a bit questionable would be the background-color-white, text-color-black and the text-weight-bold. But at least those are easy to recreate if necessary and maybe they are ghosted duplicates anyway. (An odd bug that Webflow sometimes creates where the class name is the same as another class - even though it should be impossible to do).
So yeah, generally - should be no issue cleaning up styles - definitely recommended to do so!