I almost exclusively move with Space and fight holding Shfit. I absolutely hate if I left click and one of my guys clicks an item or mob while the rest move, which made it worth it for me to do this over the old method ... which I used for a long time before learning about Space. It took some getting used to, but certainty is a good thing.

I use the Hold to Control Hotkeys to interact with each window individually when needed; I configured these to F1 through F4. So to move only window 2 in a pinch, I will hold F2 and either click (which is fine for 1 window at a time) or use Space.