That looks like a fun overcoat to have, though it must weigh a ton. But very warm, I bet. I think Mariano's gloves idea is kind of silly and that is what the hip pockets are for. Especially since any gloves suitable for the weather that that coat is made for will be pretty bulky.
While I don't love the belt width, I think there are only two things that bother me. First, I would prefer it to be a bit longer - say to shin length. Second, the collar is huge. I know why it is like that - you wanted big lapels and you wanted a closed notch so the collar would be flush with the lapels. I would have preferred you played with a notch and maybe a different collar shape (like a rounded ghillie). How does the collar look turned up? It looks like it will be well above your ears, like some sort of superhero costume. I suppose you can argue that is functional, but so is a hood. If you have time to photograph it with the lapels closed and the collar up, that would be interesting. While I am sure you won't agree with me, if you wanted to try a different collar shape , it looks like you could easily do so given how big is what you have.
It looks to me like the back pleat is meant to be that way, though I can't understand why that was the choice. It is hard to tell from the photo but it really doesn't look like it is pulling because you gained weight. But maybe it is opening because of the bulk of the cloth, which might still have a little stiffness.
Edit: I take it back - if you look at the lines of the pattern, they follow the pleat and hang at an angle. It is cut like the pleat should hang straight. If it were meant to hang open, the way it does, the lines would fall straight, but would be at an angle to the open pleat edge. I still don't think it is a result of mis-sizing - I bet the cloth is just very heavy and a little stiff and the pleats need to be pressed closed.