As far as I know there is no way to decrease the size of the spacing between taskbar buttons using WSB.
The spacing is there for people who use the Touch option.
But you can bring back the tight Vista Quick Launch spacing in Win 7 using this method:
http://www.sevenforums.com/tutorials/888-quick-launch-enable-disable.html and unpinning all icons and put them in your new Quick Launch.
As far as the buttons..I don't understand your question. Maybe a picture might help? Do you want tiny buttons? Just alter the TaskItemButton images. But if you make them too small then the text on your Uncombined Buttons will run over the Button width ( they seem to inherit this from the Combined images). You can do it but it's a tedious measuring process.
Hope this helps?