To use Mocap itself you don't need 3DXchange; iClone is sufficient. 3DXchange only comes into play if you want to import characters from other applications (e.g., DAZ), which need to be converted. The FBX export function of 3DXchange (which requires Pipeline) is only needed if you want to export characters with animations for use in other applications such as game engines (Unity, Unreal).
I would recommend 3DXchange Pro in your case as it also allows you importing assets from 3DWarehouse, which is a good way to populate your scenes with props, buildings, etc.