Your edits are stored in the catalog database. Your original photos are stored wherever you put them or wherever you instructed Lightroom to put them, probably (based on your description) on the internal hard disk. The edited photos do not exist unless you exported them, and are pretty much irrelevant to the problem you are trying to solve.
The problem, as I understand it, is that the photos are on the internal drive, and you want them to exist on the external drive but still usable in Lightroom. If that's correct, you want to move the files to the external drive in such a way that Lightroom can still make use of them. The steps are:
- In your operating system, COPY (not MOVE) the entire folder hierarchy of photos to the external drive.
- In Lightroom, right-click (Control-click on a Mac) on the top level folder in the Lightroom and select Update Folder Location and point to the new location of the photos on the external drive
- Once you are 100% sure you have done this properly and everything is working in Lightroom, you can use your operating system to delete the photos from the internal drive.
More details and screen captures of this process can be found by scrolling down to the section entitled "Part 2 — Updating Folder Location" in this document: Adobe Lightroom - Find moved or missing files and folders
I guess you are right. I talk about two different problems.
I guess the answer I am looking for is : how do I export the catalog database with ALL my edited photos? (12000) and what is a good way to organize them apart from the original files?
how do I export the catalog database with ALL my edited photos?
I am not aware of a good reason to do this, unless you intend to stop using Lightroom, which does not sound like your original question; so my advice is to not do this
If you want to know how to make backups of everything (is that the real question here?), you make a backup of the catalog file and a backup of all the photo files. This should be done on a regular and automated basis. Lightroom has a function you can turn on to make regular and automated backups of the catalog file. THere are many third party utilities that can make regular and automated backups of your photos.
what is a good way to organize them apart from the original files?
As stated above, don't do this.
It's still not clear to me why you are asking these questions, what do you want to accomplish (don't explain the steps you think will get you there, explain the end goal)
I would like to have images for my family ready to view whenever they like without going thru LR.
I would also like to view edited files on my other devices that do not have LR installed
Ok, there are many solutions to this.
My solution is to upload my photos to Flickr, so anyone can view my photos from just about any device. If there are privacy concerns, you can limit who can view the photos to only those people you allow. There are other photo sharing services as well.
Another solution is to use Lightroom CC and then anyone can view the photos from most devices.
All of this (Flickr or Creative Cloud) can be managed inside of Lightroom. Once you start exporting photos, you have to manage this outside of Lightroom, you've created a whole new task for yourself, and will be using up a lot more of your hard disk.