How to add more than 7 links in the shortcuts bar?
It's the shortcut_max_slots() function that makes that decision; fortunately that function wraps around the return of a variable from the database (also called shortcut_max_slots), so you can simply set that variable and be done with it.

There's no way to make it unlimited without hacking the shortcut module directly, so you probably want to go for a high number:

variable_set('shortcut_max_slots', 100);