OK. My first post. I was forced to upgrade Lighroom with my new Mac. I entered into the LR and LRC vortex without really understanding what was stored where and how sync worked. Is there a clear site that goes deeply into this?
So I loaded my 6000 file catalog into LR to start and of course they did not fit in 20 GB limit. I did like some of the LR features so I decided I wanted to have only a few synced collections.
I have stopped syncing all named sync collections in Cloud on LRC
IF I delete ALL LR photos and start again will they delete all my LRC photos? can i stop this?
Can I deleted all pending load photos? If so how do I find them in LR?
SO how do I just sync a subset of photos with collections?
We can't fully answer your questions until we fully understand what you did. You said that you "loaded your 6k catalog into Lightroom", but how exactly did you do that? Did you use the catalog migration tool in Lightroom, or did you start to sync all the images from Classic to the cloud, or did you try to import/add your photos directly into Lightroom? It's important we understand that, as the consequences of each of those actions would be different, so to "undo" what you did really requires knowing what you did and what the current situation is.
However, you can rest assured about the first question. Photos can only be deleted from LrC if you do that yourself in LrC, i.e. removing images from the cloud cannot delete images from LrC.
There's no such thing as "smart catalogs" in Lightroom (either version). LrC has smart collections, which is maybe what you mean, but unfortunately smart collections cannot be synced with the cloud. Only static collections can be synced in LrC, and they would appear as "albums" in Lightroom.