I can infer that he is making fun or Donald trump or he is Donald. Either way he is not getting voted in 2020
Is - two billion dollars is a unit, one unit so it is singular and you use the singular verb
think - scientists is a plural, therefore, you must use the plural verb form of think
To provide possibly past events in the songs or to give information to the people watching or help to pass the time and make it a little fun and not so depressing when times are ruff. Kinda hard to explain it's more so of what your view of the songs and the scenario of which the song starts.
Yes she does come visit the Coates
