The custom widget you had supplied the inclusion of the widget JS. I simply removed that and seams to of done the trick (note in my previous replies I said to omit that as CB Connect includes it for you).
I understand what you say about the the built-in field, compared to the custom widget. My only hiccup is that it's not the same width as built-in tweet box. Any chance of a slight modification, Kyle?
Nope, sorry; I always use the defaults that the social sites provide for best results.
You maybe able to use an IF substitution to check for twitter user_id to enable or disable rendering of the widget. Example as follows.
[cb:if twitter_userid!=""]
WIDGET HERE
[/cb:if]