Vampire asks me in an IM:

Why are the corners of the textarea gutter now blue in Metal theme?
Somehow I think this draws too much attention to those areas, it is the same color as e. g. for a selected Tab

To allow Dale to move the "close" button of the blame component into the corner. 
I don't know anything about colors but I agree it wouldn't be as noticable if we changed the color.

And second, are the changes to the Splash intended? If I now start jEdit, the Splash shows no progress or messages anymore but just sits there until jEdit is loaded completely. And if I know open another file in jEdit from outside, also the splashscreen is shown while it shouldn't as jEdit is already running and is just told what to do.

I can see progress and messages but the progress bar isn't as dark as it used to be.
The splashscreen is shown in situations where it used to not be, that is also true. But since it is not always "on top" it doesn't bother me as much as it would have before Eric Le Lay's change.