I do not find the shadows distracting ,I find they give depth and more intrest ,the slight tilt ,well I hope you don't mind i tried a crop that i think works it is a 13X18 crop . the colors & clearty of your image are beautiful , I would not touch them .Here is the crop ,it you want I will remove it, I just find it easier to show what I mean rather than trying to explain it .
I think that with this crop the shadow that is causing the appearance of a lean is less noticable .