Oh my dear! If I were you, I would wear this dress day&night!:-)
BUT I can so relate to your worries ref. that specific side view...
I have it too, just much much more accentuated as additionally to all yours, I have large hips+accentuated upper thigh muscles to front (from performing ballet in my youth) BUT a flat bum(almost non-existent from side view) AND, if not cared for, a genetically inherited bad posture(overstretched knees to the back(remnant from years on ballet, too)+ lordosis, wich result in protruding hipbones----and...belly).
Of course, I'm now overweight and mushy-but really, this annoying side view is there even when I remember to correct my posture and even when I was slimmer and better toned if not cared for my posture enough:-((.
I just try to size up in dresses like that (this can help sometimes with clinging less), layering a jacket/cardi over it (also helps distracting from crucial points) or just ignore the side view:-).
Oh, came back to say, I have the same experiences ref shapewear. Beyond that feels miserable on when it's hot does not help much here but a full/or half slip would rather help with non clinging, just try it!