One of my issues was when I was rendering the shadow pass frame it looked as though the shadow was 3d even though the primary visibility for the initials was unchecked. I troubleshooted this by unticked the cast shadow which resulting in the below result. However when I tested this later on in my progress by ticking it again the 3d shadow was not there. So I do not know if this was a bug in 2015 or just fixed itself.
Below are some of my experiments with the shadow. I edited the ray trace shadow attributes as well as the light. I wanted it to match the real image and therefore needed to see where the light was coming from, and how other shadows looked. It seemed the shadows in the real image was quite grainy so I tried to match this.
Here is one the rendered frames as you can see the typeface was quite huge which I scaled down, back in maya.