I really don't know how much this will help you, but it helped me. I did 3 drunkards paths. When I sewed the curves I did NOT pin. I found it harder to sew them with the pins.
I also placed the smaller curved piece on top about 1/8-1/4" above the larger piece. When I finished sewing those two together I had to trim them down because of the extra hanging over the edge, but they turned out perfect in the end.
I think you blue and green block looks great! I can see the problem in the pink, but it's not so bad it couldn't be used.
Lynette