I don't know if it was intentional however, I felt frustrated that when I was trying to creep forward with multiple Purifiers. Instead of moving to their next point before rooting they immediately rooted even though I had shift pressed.
You are correct that the "command queue visualizer" doesn't draw anything on screen yet to demonstrate a planned Unroot or Root command. You'll just see the "Move" lines in this build.
The purifier can have an Unroot, Move, Root command sequence queued, though if you type the key sequence.
You are correct. I just went through another bot game and it seems to work. I don't know why it wasn't working previously.