bending sideways when doing Handstand Wall Run

I) when I watch the wall run video video I notice that the athlete bends sideways at his waist when he raises his arm to touch his shoulder. I wonder would I get any significant benefits if I do wall runs without bending sideways? or maybe it's just not worth the trouble? 

II)I noticed that when I do wall runs in a straddle handstand against the wall the movement feels much more stable, is it necessary to keep the legs together? I can't see the athlete's legs in the video, in the very beginning of the video before he starts doing wall runs he's holding them together but it's not immediately apparent what happens with them afterwards.

Thank you in advance

I) Don't overthink it.  It's just a balance thing.  The closer together your hands are, the less you need to shift your hips to balance.

II) Enjoy the instability -- you're getting better at a legs together handstand while you're doing these, which is the goal of H1.