Handles for bezier curves (spacial interpolation) missing

Only the layer/transform/position path is visible in the comp panel. Other properties like Anchor Point and effects that have position properties are visible in the Layer Panel if you choose the correct option. Unfortunately, there is no way to open a Shape layer in the Layer panel. It's a feature request that I have filed numerous times.

The only real option is to tie the position of a null to the Transform Elipse 1/Position property with an expression. This one will work if the Shape Layer Anchor Point and position property are at the default values.

p = thisComp.layer("Null 1").transform.position;
p - ([width, height]/2) 

The expression gets a lot more complicated if you need more or to also animate the shape layer's position. I don't want to try and write it without testing it in AE first.

Try highlighting or clicking on the keyframes which you would like a handle on.