I’m glad you’ve got the shadow issue under control.
With regards to Hair materials you’re probably going to run into a little bit of trouble at the moment. There are plans to make this better in the future though as mentioned by our Trello Board UE4 Road Map (Trello).
With a masked material you will only get the hard edge. With Translucency in the editor right now there are improvements that still need to be made to get the best results. Some people have managed to do some decent work, but it’s not as easy to use translucency with deferred rendering as it was with UE3/UDK’s forward rendering.
The best solution I can offer at the moment would be to look at what others have managed to do in the forums and AnswerHub.
Click on the Answers or the Forums to only look at those areas.
Thanks!
Tim