Her right arm seems to be at a possible, but uncomfortable, angle.  It doesn't feel like it's going forward into the background enough.

The left arm simply appears too short and the wrist looks like a painful position as well.

His height should shift up and down during the walk.  When the legs are straight below him, perpendicular to the ground, he would be at his tallest.  Likewise, when one leg is most forward, and the other most backwards, he should be at his shortest.  By having him stay the same height, you are actually making his legs stretch and compress unrealisticly.

For the jump, he should definitely bend his knees prejump.  To simply fly off into the air like that is impossible.  The exception to this is if you want instant reactivity, like in super mario brothers.  In which case you would need to use a good jumping sound to give it life.  Of course since this is just a "if I ever make a game" stage, yeah, knee-bend

First the arms... they should swing at the shoulder, not the elbow.  There should be very little or no elbow swinging at all unless she is powerwalking.

Next the legs. . . you did a good job with the light/dark shading for depth, but the legs need to get shorter when they aren't perpendicular to the ground, and especially the lower leg when the foot is picked up. . . speaking of which, the feet need to come off the ground.

His chest is flat and shoulders nonexistant.  The cloak is definitely the best looking thing.  It looks alright, just really un-refined, especially in the face and feet