Hmm....

Aperture should not affect perspective, subject distance will. 85mm is considered perfect for headshot and I am not sure if a longer lens would help much here. Try different angles next time, it could just be that the post is simply not suitable for headshot. Try it on full length?

Overall, I think it is a pretty decent set. Still think color is the bigger issue. Oh, you happened to embed Adobe RGB profile with the photos which may also cause issue with other browsers that are not color profile aware, consider sRGB for web. Viewing the set using Firefox improved a bit but still off.