Wow, whiny. I was pointing out that you don't need the source code, the SDK code is sufficient.
And yes all of it can be done, not "most", ALL.
More to the point, nothing mentioned here is even hard to do. The new model for the grapnel hook and the animations would take the most time.
I don't see any value in these suggested changes. But if you want to do it, go for it.
I would be happy to help if you get stuck on something.
Also, I don't think you know what "Pandora's Box" means.