Im not huge on the curve change on the besier curve node icon. I like the thicknes, but it didnt need to become perfect U's.
Also, for the join-node icon, its nice that you reduced the number of elements, but the nodes should be joined to show the end result. Right now the join and unjoin look the same with the arrows pointing different directions.
So it should be like:
← →
o- -o
And
→ ←
o---o