We powwowed the bugfix on the private forums being able to be shared lol; to customize the buttons in the shareaholic bar you'd do that from their site (as that's where all of the config information goes anyhow); you can add a whole plethora of buttons, even an "other" button (which you can see at UBBDev or A Gardeners Forum).
There is also a modification over at UBBDev (
here) that covers adding this mod to other sections of your forum as well.