OLE Objects

Is it possible to embed OLE objects in a GoDocument/GoView?

I’m not sure what that means, since OLE Automation objects aren’t Controls.
Your application can certainly be an Automation host/container, and you can create Automation objects and associate them with your diagram’s GoObjects (presumably nodes), and you can call IDispatch.Invoke on those objects as you see fit.
I assume you have seen what we did in Sanscript, which is a freely available product for you to learn from: http://www.nwoods.com/sanscript