Just a point of clarification.
Why you discuss backing up your catalog, some people use that to mean "all my photos". If that's what you are talking about, you are missing a key element.
Other people use the phrase backing up your catalog to mean the "all my photos and catalog file". If you mean it that way, then you have done a complete backup, including keywords, collections, edit history, virtual copies, etc.
For the original poster, who spent a lot of time cleaning up keywords ... if you use collections at all, or virtual copies, or color labels or stacks or a few other Library module functions, you must back up the catalog. The writing of metadata (keywords, captions ,etc) to the individual files will NOT store collections, edit history, virtual copies, color labels, stacks and a few other things, and the only way to back this up is to make a backup of the catalog file itself.
The only safe way to back up all of the work you have done in Lightroom is to make a backup of the catalog file and all your photos.