Good learning experience, though one might argue that the original design should have noted those sorts of important aspects, rather than expecting them to be obvious. Probably would have saved you both some effort.
No, but I might include a general note on alignment. And rarely is literally everything going to be aligned down the left side of the page, so you could also include some annotation to show what's aligned to what (and maybe why).
I'm no designer, but I know I appreciate when designs include that kind of info.
