Thank you all for your crits.

Arms are unrealistically tight with the body. Legs are too long. Shorten the upperleg so that the fingertips touch the top of the knee, and scale the lowerleg accordingly. Make sure your feet fit about 1.5 times into the lower leg.
I agree with you on the arms. The legs seem fine to me, four heads to the crotch region... I'm not sure where the fingertips touching top of the knee comes from, my body and a few charts I posthumously consulted seem to contradict that. Feet are an issue with me, as I can't reference my own body because my feet are essentially as long as my forearm and I'm reluctant to believe that's the norm, thanks for the proportional guideline.
Note that knowing proportions won't do. Whatever you draw, I actually recommend to find some sort of reference to get your perspective right. I tend to be able to draw a pose from a certain angle from my mind only if I drew it from life once, I don't know how this is for other people, but basically I'd have to draw every possible limb from every possible angle at least once to be able to draw anything without reference correctly.
For the past couple months I've felt a sort of artistic stagnation which I believe has a direct correlation with my dependency on references. I can draw from life and from photos well enough for my purposes (for now) but when it comes to imagination/creation rather than reproduction/interpretation I feel my art is lagging significantly. So now is my attempt to remedy this by confronting my deficiencies as an artist, even if it means 'regressing', or rather, abandoning my comfort zone in order to learn new things.
Yeah, sorry for the little monologue. Once I have a firmer grasp of proportion and shapes and overall construction I think I'll be set...
Both arms might actually be too long, with how they're bent, actually.
Yes, I agree. My application of proportions in general is far two two-dimensional, I need to work on some foreshortening I think.
Ryu's post
Thank you very much for the edit. What you did with the arms and shoulders is very good. I will make some more things soon with your advice in mind. I'll be trying to make some more dynamic stuff soon also.