I’ll agree number three is the best by far. In the others he either looks too stiff in the suit or he has that fake smile plastered on his face. A reflector on a small stand will help with the light in a few of these as at the moment they look very flat for the most part. Put a shoulder sling on your stand and it is easy to bring with you and if you can bring a speedlight which you can bounce off the reflector if need be.
If you can’t get good results when you AFMA your lens manually maybe consider investing in reikan focal for about $60 which does it for you. The 50 1.8 has a shallow depth of field which takes some time getting used to and you have to be careful about focus point selection. Focus and recompose doesn’t work well. I’m assuming you have the camera in one shot mode.
As for upgrades, I think the 85mm f1.8 probably makes more sense than the 50 1.4 as it would give you a different focal length to play with. Outdoors the 85 will perform better as it can do shallower depth of field but you can still back away as it will feel a bit long sometimes. It is also less fragile (if you look at the 50 1.4 the wrong way it may stop autofocusing, ok slight exaggeration)