I've modified your code to already add a lost password and register button after the login button:
in the php file:
<input type="button" class="adminbar-button" value="'.__('Lost password').'" onclick="location.href=\'' . get_settings('siteurl') . '/wp-login.php?action=lostpassword\'"/>
<input type="button" class="adminbar-button" value="'.__('Register').'" onclick="location.href=\'' . get_settings('siteurl') . '/wp-login.php?action=register\'"/>
and in the js file, I added a code that when you hide the bar, it doesnt leave a gap on top, but slides the html/body also to the top:
$('html').animate({'margin-top': '+=28px'}, 'slow');
$('body').animate({'margin-top': '+=28px'}, 'slow');
And of course the -28 in the other condition.
Would be cool to see these as an official addon. Nice work so far.