Well, I changed my user-dirs.dirs back to the original state, and did the bind mount from my data partition to my /home/scott/... user directories. All works fine.
Despite the fact that my GLib2 version is before the version that fixed the "fstab binds appear as mounts (x-gvfs-hide is being ignored) (#1271)" bug, I don't have the bind mounts showing up in any of the file managers I have available, EVEN IF the x-gvfs-hide option is NOT listed in each fstab bind mount line (I tried it both WITH and WITHOUT the option). I suppose I should assume that the bug fix (since bug #1271's fixes were done seven months ago) was back-ported to the version on testing/sid. I tried GDebi-ing my current debian GLib2 libraries into Peppermint 10 system, to test this theory, but each one of the three packages pointed to one of the others and cited incompatibilities. Possibly I should un-install ALL THREE of the default ones first. instead of having GDebi replace each with the newer. No time now...