To 1.
I think a good work around for this would be to create an asset with a curve, instantiate it, and then in your asset use that curve asset as an input asset.
I'm not entirely sure I understand. How would I implement curves of varying amounts of CVs?
A great Houdini-level work-around would be if we had a curve parameter. It could be something similar to the add node, where you can add and remove unlimited amounts of points.
Edit: - I just saw that the add node uses a “Multiparm Block (list)” parameter and it seems to work in UE4. So that could be turned into a sufficient work-around.
To 2. Basically I just export a thin polygon strip. Because UE4 does not seem to import NURBS curves or (Houdini) polygon lines. I can convert that thin polygon strip into a curve inside the HDA.
My actual question should be: How exactly do I get geometry into the HDA inside of UE4?