No, as of now there is no fourth season of Black Butler.
Yes, Black Butler season 1 is available on DVD.
Alois Trancy is from Black Butler Season 2.
Unfortunately as of now there are no plans for Black Butler Season 3.
The opening theme to Black Butler Season 1 is 'Monochrome No Kiss' by Sid.
The theme song for Black Butler Season 2 is "SHIVER" by the GazettE. It is used as the opening theme for the season.
24 Episodes in season 1. 12 Episodes in season 2. ^^
Black Butler Season 2 has already been released both in Japan and the United States.
There has been no date given as to when Black Butler Season 3 will be airing on Netflix.
As of now there will not be Black Butler Season 3.
As of now, no.
yes
Alois is a co-antagonist in Black Butler Season 2, and an important character to the plot and storyline of that season.