...About the last three not being sharp. 1/5 motion blur doesn't help either. I sometimes deliberately focus off the eyes--like on the lace of the bra with just a hint of the facial expression out of focus. I'll even cut off half the face, leaving just the lower half.
Admittedly, I'm more of a creative candid shooter, not a portrait shooter. I hope to move more into portraits soon. My 50mm f/1.8 blows at 1.8. I hope to get an 85 f/1.4 in the near future--after I sell my Contax/Zeiss equipment.
I shoot at f/2.8 all the time at weddings--and often with natural light. Other wedding photographers are frequently doing the same. Tommy Colbert is one who motivated me to try the combination more. I however have not reached anywhere near his caliber yet, and I doubt I ever--especially if I don't take this job on full time.