The main issue in the thread just seems to be peoples differing perceptions of what a tweak is.
I would say yes, there is probably room for some refinements. To me that means that some of the headers might be reduced by 1 or 2 pixels, or a line might move up 1 or 2 pixels. Which is fair enough, that is a tightening of the OS that wont affect the usability or visual style of the OS.
A lot of what has been suggested here would be total over hauls of the UI, a re-writing of the Metro design language which would result in significant change across not just WP7, but also Windows 8 and Xbox. The Metro style as far as its key principles are set in stone now. You might not like them, but that does not make MS wrong any more than it makes you wrong for wanting something different.
Now can we all put on our big boy pants and have a civilised discussion about this or are we just monkeys throwing our crap at each other?