1
) Requires rewriting the explorer.exe, so no. But if that's critical, you may use Nyditot Virtual Display to emulate a higher resolution and thus reducing icons in size. This will, of course, affect anything and rise the CPU load.
2
) Yes, it is. With the default explorer copy a file and in the required folder
(\Windows\Desktop for desktop and \Windows\Start Menu for... start menu
) select "Paste shortcut from "Edit" menu.
3
) There is the setting to open each folder in a separate window, but that's not very comfortable to use
(too many windows
). Have you tried Total Commander? It has two views.