Whew, the recovery here was actually smoother than I expected and everything SEEMS in pretty good shape again.
Huge thanks to @CharlesGreen for an explanation of how that command extended up a directory. Also thanks to @Panther for info on getting into recovery mode for a somewhat related issue. (if you both want to re-share your comments as answers I'd upvote them)
Fortunately, unlike the linked post, this seems to have had a very straightforward fix. It seems when I ran the sudo chmod 600 .* command from only one directory under / it expanded the .* portion UP to the true root directory altering permissions of . from / causing every other permission to fall over.
The "fix" for this was to boot into recovery mode, re-mounting the drive as read/write, going to the main root (cd /), and then chmod +rx .. After a reboot, everything looks to be back to normal.
Moral of the story, executing a command on .* can at least sometimes impact the directory ABOVE the current. I had intended to only impact files that started with ....oops.
Huge thanks to everyone that commented and helped.