[\] Would that come close to what you are saying?
Thank you for your time,
Your exercise with the bag nicely illustrates part of what I'm talking about. Arranging yourself to fit its trajectory without interference, perhaps helping it go where it will, is certainly part of the puzzle.
Alternatively, you could catch the bag at the limit of its swing, climb on, and ride with it. This also would cause no interference (if you manage it smoothly), and would, like my pendulum example, help you understand both its limits and its degrees of freedom.
By yourself, you are like the bag in that there are ways you can move and ways you cannot, unless something becomes broken or severed. The bag is pretty simple, but we are more complex. It really helps a great deal to map out our own limits and boundaries of freedom (see http://www.aikiweb.com/columns/rrobertson/2004_03.html)
When you interact with anything, whether it's a punching bag or another human being, the two of you come together to create a new system. This system now has new limits and new freedoms, and changes the basic map of the individuals involved.
As a simple example, imagine holding hands and walking with a close friend. So long as your hands are clasped, the arms remain free to swing between your bodies, but a little further away than when walking by yourself. But unless you let go, the act of scratching your ear will be very different than when you try it alone.
This is easy to manage with a friend. Two bodies become one and seek to move in a coordinated harmony. It is much more difficult to do this with an enemy who is actively seeking to harm you. Yet if you can be the part of the system that keeps everything in balance and oriented towards a normal range of freedom, then the combined body or system will continue to operate coherently.
This is a much different approach than going in with the assumption that we must throw or pin. These things also have their place, not unlike how we might want to put our own leg in a cast if that part of the system has become broken. Yet the goal is still to return everything to working order as soon as possible.
I hope this helps somewhat. The short answer is that, yes, by doing the kinds of experiments you are doing, the thing itself will teach you how you and it can behave well together.