Well, it turns out the tensioner just needed to be man-handled once the timing belt tension was set. The little fork thing still didn't move when I moved the hex thing, but like in the 2nd video above, it moved if I squeezed the belt.
Thanks to a neighbor who as been a mechanic several years, I now have a running Focus again.
(Man, that timing belt was bad...cracks everywhere. I was definately on borrowed time with that thing!)