I'm not part of the development team, but I would prefer location 3.
This is because I think it will be too cluttered to have the changed lines in the file list view.

Of course it might be nice sometimes to see the number of lines that changed, but for that I think showing it in the diff view (location 3) is good enough.

That's how they do it here on github as well (display it in the same place as the file name in the diff view):

I updated the PR to include the number of lines changed on files:

I agree with @DarkDefender. For me, the count of changed lines is useless.

And in the INFORMATION view, the STAT part is easy to cause misunderstanding. I think most people will more easily understand it as "Added X file(s), Modified Y file(s), Deleted Z files"

I would like this, both per file as well as in the commit overview.

And in the INFORMATION view, the STAT part is easy to cause misunderstanding. I think most people will more easily understand it as "Added X file(s), Modified Y file(s), Deleted Z files"

I disagree. If you would add the number of changes files as well, the proposed format is exactly what the widely known git show --stat and git show --shortstat displays.

This is how it looks in Sublime Merge, with a tooltip to explain the numbers: