I am working on this one.
Don't kill the transcript, it is useful when working without a console.
Now, adding the features you mention is not hard. And the top right triangle menu of Transcript could get a clue from the Workspace one with a Save As entry.
I once had an issue with things like (out of the top of my head) FileStream stdout nextPutAll: 'hello'; cr; flush. when I went headless. The image worked at one point and the froze/locked. Until this is sorted out in full, keep a transcript handy.
I gave the image to Guille who sent me back a version "unlocked" with Oz, but it still dies on Windows for example. Weird.