Hello! my fault for non answering earlier, I'll answer what I know (: (the procedural part is beyond what I usually do)
You can bind a path to follow a bone by selecting the path, opening the weights panel, bind the bone and then edit the weights of the path so thato one end follows the bone you chose and the other the parent bone/a bone of your choice. Paths - Spine User Guide: Weights
At runtime you can move bones around programmatically, which will affect the path exactly like it does in Spine.
Each skeleton is exported to a separate file, you can't do a data export with only part of a skeleton, but note a project can have multiple skeletons.
Export - Spine User Guide and Texture Packing - Spine User Guide might help you.