Idea fase, simple idea, Finn walks and stumble upon a rock in his path, he thinks for a moment and decides to move it out of the way. He lifts it up and tries to throw it out of the path, but the ball/rock is too heavy and falls straight down onto the path again.
Block
Animated walk frame by frame before animated with pose by pose when I did the lift.
On the walk I started out by figuring how many steps I wanted him to take before he got to the rock, and then I moved him approximately the distance away from the rock. After that I made a simple walk, starting with the feet, then animated the arms and ended up with the hips, spine and head. Later on after I blocked out the lift I went back and fixed what needed fixing on the rough walk.
With the lift I began blocking in the key poses without thinking on the timing. After moving him into each position I moved the keys to different frames and kept looking on the animation and moving the keys until I got the timing down. Then I could fill in the details between the key poses and get a smoother animation.
Going into rough is always tricky, and I like to often block with auto key and don't do step key, I did do step key in this case, but I'd rather not normally. After I gotten down the main movements I started on the feet and hands (fingers) to make it look slightly more realistic, and I also added some hip movements and a minimum of shoulder moments. The ball I animated by itself and didn't link it to the hands, I find it better to have it work then having a small change for something glitching up because I wanted to go the quick easy route. The rest of the time I spent on making small tweaks, but left most of the initial animation alone.
Going into rough is always tricky, and I like to often block with auto key and don't do step key, I did do step key in this case, but I'd rather not normally. After I gotten down the main movements I started on the feet and hands (fingers) to make it look slightly more realistic, and I also added some hip movements and a minimum of shoulder moments. The ball I animated by itself and didn't link it to the hands, I find it better to have it work then having a small change for something glitching up because I wanted to go the quick easy route. The rest of the time I spent on making small tweaks, but left most of the initial animation alone.

As i read it now it seems like you have done the block in 2 parts, first the walk then the lift. Not a dumb thing. But be sure not to focus to much at the walk when the lift is the main part in the assignment.
SvarSlettAlso, try bend your wrist 90 degrees down, as your rig is doing in the middle image "lift"
Still just a block so i bet you have done allot of tweaks already. Hope to see more post. Good block.