1) When there is an error, the debugger opens directly. Reason: I found that I always press Debug when an error occurs in the Notifier window. Question: Should this option be a preference?

I like VW behavior. There are three buttons: debug, run, step.
When I do debug and there is an error in some test, the debugger opens directly. And when I press debugger proceed, tests continue execution.
When I do run, all failed tests are collected to the list. And button "show failed" appears.
When I do step the debugger open on the begin of test.

I think it is ideal browser behavior for TDD support. In some squeak version (maiby 3.8) there is special services fo this. But now it is absent