You can have instance like setup but there is a limitation. Nodes currently can't process complex input hierarchies, they can work with immediate chldren objects. There is also an option to use symmetry node as well. Here is an example that mimics instance
Quad Mirror Start_0001.c4d
Depends on what you want to do. I presume here you are looking to read out the value. That can be done by using a nodes mesh (pr spline), do your calculation in graph and pass it to name of a tag (say weight tag). That way you have a tag in OM with name which is the actual value and can be accessed
Took a quick look. Was a long time ago when I was into animation but I believe your issue is due to pivot object. You can go around it by setting a key on Z for bot null (your retargeted character), but your keyframe has to be in step mode to compensate for the change your are making with pivot on or source character. Could be that this won't be desirable for you and that are other solutions, hope this helps 🙂
Yes, you can use rope dynamics with fixed points, however, usually dynamics are not used with these types of rigs, depending on the shot need. Handbag straps are quite rigid and for them to be fully art directable dynamics are often an overkill.
Would be easier with example scene, to see where you are 🙂
Explode mesh islands with get count node will give you that information
No built in way as far as I recall at the moment. You will have to construct that
Can you attach what you have so far? Also, does the boat need to change orientation according to waves? Presumably, when you say static you mean anchored but still responding to waves