Clearing the Library

In an effort to speed up my LR experience I am curious if on my system a clean library would assist, therefore I need some exporting catalog or clean up advice.

I already have a pretty odd LR setup with how I manage my HDDs and stuff, 80% of my library doesn't work anyway because the original image file is no longer there (moved to another hdd).

My library says I have around 3427 images (that's what it says on my most recent import, a transparent '3427' kinda behind the thumbnail). I do use the Library feature, but only for a few sessions at a time. Once my internal SSD's get to full I migrate the RAWs and Exports to by backup Quaddock (holds multiple HDD's and is not left on all day as it is noisy and drains unnecessary power).

Perhaps it will help explain my workflow. It is important I don't want advice in this specific regard, I deliberately work like this to avoid having to constantly have 8TB's worth of HDD's whirring away for 90% of the time unnecessarily, I enjoy the low noise performance of my Skull Canyon NUC (which has an SD Card slot ).

• Take photos on camera (writes to two cards simultaneously).
• Eject one SD Card from camera, put in the NUC
• Use Faststone Image Viewer to browse the RAW files quickly, tagging the keepers, I find this far far more fluid than importing a massive volume of files in LR and dealing with the cull at that point
• Once I have tagged my keepers I use a feature in Faststone that moves those Files/Images to a new location (ie from the SD card to a Folder on the C:)
• Eject SD Card from the NUC, put back in camera
• Using Faststone Image viewer again, fire up the first image I want to work on in LR, I simply click 'E' and it opens the file in LR (prompts the Import).
• I import, edit and Export the image
• However, the C: is only a 250gb SSD, therefore around about every week to fortnight I need to Move both the RAW files and the Exports to my HDDs, to give me back 'working space' on the SSD. This however is much more preferable to me as it means I only have to toggle the HDD's once a week/fortnight for a few minutes. Bypassing the SDD and instead use the larger HDD from the outset not a viable option to me, it means I would have to toggle on my external HDD's daily, it completely negates the idea and premise against the purchase of the low powered/quiet NUC in the first place.

So that's what I'm left with, a LR library of hundreds of images, of which I still have all the files but the library is not able to find the files anymore as they've been moved.

I am hesitant to delete or wipe the library because it could be one day I want to go back to an edit rather than start from scratch again, I figure there must be a way to tell LR to also check 'here' (and make it point to my HDD where the RAW file will now be), and then proceed with the edit, or failing that manually find the image on the HDD and drag it back to it's original location on the SSD so LR can 'see it' again.

Truth be told I have not had to do either of those two things yet, however I like to be safe rather than sorry.

I mustn't be the only user using LR like this. People whom use it on laptops or tablets with limited internal SSD space, they must also have 'broken' libraries?

So two things;

1) A library of 2000+ is silly anyway, so many images, I can't find what I'm looking for easily, and I get a sluggish 'searching' experience

2) I'm hoping that clearing the library, or at least canning a certain amount to leaving the last 200 images or so still there will lead to a quicker navigation and less sluggish LR experience. I'm sure if my PC had proper processing power this might not be such an issue.

So how do I empty my library in such a way that should I want to work on an old image I can 'import' my old library (catalog?) and then either point it to where the file now exists or manually put the file back to the SSD?

TIA!