Hey FL,
In regards to the neckline, I think it is personal preference so if you are happy with it leave it where you have it. That being said, I personally like the neckline right along that transition point between the head and neck so I would tend to agree with Margus and Ncbeardguy that you could raise it a bit. For me, defining my own neckline took some experimenting before I was happy with the position and angle I had everything defined at. Going by your pics, this is where I would estimate placing your neckline:
And it would look something like this:

Hope that is helpful. As I said before, you did a great job trimming.

We live as though the world was what it should be, to show it what it can be. - Angel (Season Four)