.DS_Store files store the view settings for the Finder. Deleting them will restore the default view settings and you will lose the file comments.
.localized files mark a standard folder as one that should be shown with a localized display name. In English that usually is the same as the file system name, but in other localizations the Documents folder might display with a different name for example. The .localized files themselves contain nothing. They are just a marker, a flag. There is not real harm in deleting them, but it doesn't do any good either. You shouldn't delete them.