To Move windows' close button to the left:
Use gconf-editor change key: desktop>gnome>shell>windows
To change toolbar style:
Use dconf-editor change key toolbar_style in org.gnome.desktop.interface
To change mouse cursor theme:
Use gconf-edigor to change key: /desktop/gnome/peripherals/mouse/cursor_theme
Every other workaround simply won't work, event changing the file /usr/share/icons/default/index.theme won't work.