I can’t remember what version caused the problems, but I believe that I have now, with the help of Google Support and the .insync-trash hidden folder, been able to recover all the data that I thought was lost. Thankfully, I had a complete sync of all of my Google Drive files on my workstation at the office and the .insync-trash folder there appeared to have all of the files that disappeared from Google Drive and my laptop. That said, if I had not had an instance on my workstation I may not have been able to fully recover from this incident.
Not being a software dev, I have no idea how to prevent such issues in the future, so I won’t try. But, I can say that I highly recommend taking prudent steps to make sure this doesn’t happen again.
For my part, this all started when I simply wanted to make some room on my laptop. That should never lead to hours worth of panic and non-productive work.
I have enjoyed Insync a great deal since I originally signed about a year or two ago. I have not had any issues thus far, but this episode certainly taints my impression of the app. I am not leaving at this point, but if such an issue pops up a second time I will have to reevaluate my use of Insync.