Sweet pictures and cool spot! Clean but still some obvious age.
For number one, it would make the picture look better if mainly it was squared off, but also if possible stepping back and zooming in would add some depth. That second part depends on the building, but the first one you can do in most photo editors I believe, or at least lightroom Instagram editor and the iPhone photos app editor.
Example of those 2 things:
For 2, I like what you're going for but in my experience doing super low shots like that don't usually turn out well. I personally would've positioned myself behind one of the barrels with it blurred in the foreground and used that to give some depth, rather than using the floor.
3, again go back and zoom in if possible. If not, maybe focus on a smaller texture on that face like the windows.
Example:
4 is cool but maybe a little crooked.
5 also a little crooked. Not sure how the whole scene was but that doorway looks interesting.
6 I really like, especially with the color contrast.
Hope this helps!