You're asking how to add custom fields to the postbit right?
You can do this by either directly editing the postbit_legacy template or using a template hook (the latter of which I prefer because then you don't need to worry about templates reverts in later vb releases and it's easier).
Doing a direct edit would work like so:
Open the postbit_legacy template, find $template_hook[postbit_userinfo_right_after_posts] and below (or above) that, simply add for example:
<if condition="$post['field3']"><div>Your custom userfield: $post[field3]</div></if>
Repeat as desired to add more fields.
The template hook way:
Add a new plugin at postbit_display_start and add the following code:
if($post['field3'])
{
$template_hook[postbit_userinfo_right_after_posts] = '<div>Your custom field: '.$post['field3'].'</div>';
}
if($post['field4'])
{
$template_hook[postbit_userinfo_right_after_posts] .= '<div>Your custom field: '.$post['field4'].'</div>';
}
Note the .= used in the field4 statement. This appends data to the variable instead of overwriting it.
Hope that helps :)