I am just here to talk about that shirt in #2. Others can advise you better on the other things, you could give me lessons on how to wear modern and slouchy and edgy. But button-front shirts are my thing, and we share enough (wide shoulders with a bit of apple tendency, colouring, androgynous vibe) that maybe what makes it work for me can also work for you.
In #2 it looks boxy because it looks too stiff. In fact it stands away from your waist and hips making them look wider than we know they are (cf #5). That shirt is bossing you around, and you need to make it bend to your will. Maybe it will be softer after several washings, or you could hang it in the line in a stiff breeze. You didn't iron it, did you? If you are as near the shore as I am, the humidity is enough to dissolve serious wrinkles.
For the immediate wearing issues, I would try rolling or pushing the sleeves up even higher, to beat at least one part of the shirt into submission. You might try the J Crew roll if that's more comfortable. For the body, what others have already said - - semituck, or undo more of the top OR bottom buttons, perhaps over a T shirt or something. Your can also layer over it -- a blazer, a sweater, your leather jacket-- to put it in its place.
That is what I had to do with my Banana Republic classic button-front. In the store it was way too stiff but scrunched and layered majorly, it felt enough "me" to come home with me, and now that it has been softened by several launderings, it behaves as I want it to and has become one of my favourites.
It is probably easier for me because my bust is smaller. But hey, Charlize Theron pulled it off beautifully in A Million Ways to Die in the West (ridiculous movie, but I loved her style; not the cowgirl stuff but the androgynous blending of elements, long skirt with relaxed shirt etc.)