Good work, I assume you're using IK's if so, I'd suggest raising the hip slightly as this might just pull a bit of the bend out of the knees. Easiest way to do this, select the hip, in the parameter dials, click the arrow next to Y trans and from the pop-up select graph, extend the vue so that you can see all frames (drag the bar at the bottom till it fills the space) Right click inthe graph and drag the mouse till all frames are highlighted, then hold down Ctrl, cursor should change to 2 vertical arrows, now you can move all key frames up or down. Do this in very small amounts at a time till you have what you want. I think only a small adjustment is needed. The graph should be a nice wave form as hips move up and down slightly as we step. The box display you asked about can be set from main toolbar Display>Tracking>Fast or with a small icon usually bottom left of the project window, there's a square icon which lets you set display port options. Next a sphere, turns into a sphere in a box for fast tracking or a box for bounding boxes and beside that another icon for turning ground shadows on and off