Thanks ryles,
There is a rhino command called "Close Curve" which would close any curves directly.
It d be great if there was a simple tool like that on GH.
Further to this, there is n easy way to create a curve to close them off similar to the Rhino Command BlendCrv. Use the BzSpan Component to create a curve based on Starting and Ending Points and Tangents. To get a nice blend I used a third of the distance between the two points as a Magnitude for the Vectors. I try and post an example when I get back from Lunch if you need it.
I personally would recommend the change to Icons as I found that if anyone used a component that I didn't recognise then I could see it in the toolbar as they are the same images.
The Components Used are:
End Points, Curve CP, Evaluate Curve [Curve>Analysis]
Distance [Vector>Point]
Multiplication [Scalar>Operators]
Reverse, Amplitude [Vector>Vector]
Bezier Span [Curve>Spline]