Is there a walk toggle I'm missing somewhere? Or am I doomed to have my party run everywhere?

Did you try:

"-" for slow mode
"+" for fast mode

I don't need slow mode. Just want to walk like other ingame characters. It's for roleplay.

If you double click either (so that no speed differential is shown in top central), it becomes regular speed. If that is the speed you consider "running" all I can say is to take short moves and hit the spacebar a lot. You can also set the team to stop whenever they sight an enemy or trap

I'm quite sure I read an interview with one of the devs saying that there'd be no walking speed for your group.