(Please ask one question per thread so the forum is easier to follow and for people searching for existing discussions.)
The different tree styles under Preferences / Folder Tree / Appearance have different widths, although I don't know if any of them are as narrow as the one you have in mind. The Vista-style auotmatic horizontal scrolling option under Preferences / Folder Tree / Options can make the width of tree branches less important, too.
You can have as many icons on the status bar as you want, and you can fully customize the information displayed there.
See Preferences / Display / Status Bar and the Status Bar Codes thread, as well as the Sampels drop-down in Preferences, which included a sample that only uses icons for the file/folder counts, just as you wish.
So does Opus, if you change the grid line style, under Preferences / File Display Modes / Details, to the solid block.