I really like the class mode because the very quick gestures help me get in the right headspace for gesture drawing--focusing just on "describing" shapes with lines rather than focusing on drawing a whole person performing a specific action. It's really easy to get caught up in how complex the human form is, but if you take it one line at a time you can start understanding things much better.
A lot of the areas where you've added value (shading) look really dimensional and rounded, which is great! Shading is a great way to describe the natural round forms on the body, since we're not made of lines.
I would say that maybe you'd benefit from spending some time focusing less on shading and more on proportions, especially for the 5 minute drawings. While drawing in shadow shapes isn't a bad thing to do, and in many cases actually helps you understand the shapes as you're constructing them, I think we often get caught up in the shading and "finishing" work of a gesture drawing instead of focusing on the fundemental shapes. Focusing on proportions will help you "describe" complex poses even better--for instance, the length from the tip of a person's toe to their hips is going to be different (even on the same person) when they're standing straight up vs when they're lunging or performing some other sort of action with that leg.
Measuring proportions of one part of the figure against another part of the figure (i.e. "in this pose, the toe-to-hip distance is the same as the hip-to-head distance) helps you keep everything looking believable, especially when you're looking at body parts that are often at weird angles or foreshortened like the limbs and hands.
But really, I think the best advice for beginniners (and any artist) is to keep going. Skill is a function of time and effort, so as long as you don't give up, you'll only get better, provided you're taking breaks and addressing your needs outside of art. Keep it up!
