For #2, first you'll want to add a couple of keybindings to your init file (these are the suggested keys in the Org manual) -
(global-set-key (kbd "C-c l") 'org-store-link)
(global-set-key (kbd "C-c C-l") 'org-insert-link)
then you can hit C-c l somewhere in or on the item you want to link to, then C-c C-l where you want to place the link. It'll ask you to confirm the location and then enter a link name - you can just hit enter to accept the defaults. It will create a link like [[file:foo.org::*bar][link-name]], which displays as link-name.
See http://orgmode.org/manual/Handling-links.html for more details.