What an honor, to be the one who often has to drag his three unconscious comrades from the dungeon while fighting off enemies!

Anyway, run/walk can be toggled in Grayface patch (I'm not sure if it adds it by itself, or if this functionality is a part of the Mok's patch which is included in Grayface's). In vanilla MM6 (or with the official patches only), the only way to toggle between run and walk is to put something heavy on your Shift key .