Problem 1. In order for the two events to be available in your new object (actor), the actor’s blueprint has to implement the Pickup interface. Open the object’s Blueprint, click on Class Settings in the menu bar, then add the interface through the Details panel on the right side. After that you should be able to add the two event nodes.
It may be easier to duplicate the blueprint for the working object and just change the reference to the mesh inside it.
Problem 2. Check the mass of your ball. If a physics actor has a too small mass, when you throw it will accelerate very fast and quickly disappear in space. Increase its mass and it should solve the problem.