Forrest's Sketchbook of Wondercanes and Dreamsicles.

[Samszym]

Aw ya, that pose is looking much more convincing now, nice job on the studying! Your observations seem solid to me more tense means more interested/alert in a simple way of thinking. I think "the pose looks more lazy the more things the body uses to support itself, rather than holding itself up" is a pretty smart way of looking at it.
Only thing I'd say to keep in mind is that just because a part of the body is touching something doesn't necessarily mean it's putting weight on it. But that's more relevant when you're doing an action pose and want to show something in motion, just about to leave the thing it's touching, or having just touched it

nice stuff dude, glad you're thinking more about pose language :D