Ok to delete the scratch folder?

Even though I am an experienced user of Screenflow, I still get nervous about the significance of .scc files and the scratch folder. 

I've been uploading many created-videos to Dropbox, as zip files, which I understand is the correct procedure, in order to archive and also free up some hard-drive space.  I feel confident about doing this, except that I still see a 6GB Scratch folder on one HD.

I would not be worried about erasing this, except that  only last week I opened one file that I had not opened for a couple of years (which I considered completed and published) , and got the message (whose wording I can't remember exactly) about SF having found salvaged .scc files, and did I want to load these. I can only think these must have been in the HD Scratch folder somewhere.

I remember that on a previous recent occasion I had ignored this message on a nearly-completed project, only to find later It was impossible to Save that project any longer (something about a numbered error and files that could not be "read or written"). I never managed to solve this even with SF-support help, (luckily, I could go back and work on a previous Save, though that meant a lot of wasted time).

I understand that all required .scc files ought to be incorporated in the stored SF project-file), so can someone please just set my mind at rest that it's fine to delete the Scratch folder and move all files to a different location as I have done.  Also any raw-footage and other materials  stored in other folders on the original HD, or anywhere else on one's computer and network.