Hungarian mercantiles: Yep, Hungary is landlocked so a some kind of special rule for it should be good concerning mercantiles. I'd say that you may make any duchy that borders Danube is good as mercantile, meaning Pressburg, Pest, Pecs, Szekerhervar (or whatever), Temes and Wallachia are legal choices as mercantiles.
Archbishops after game start: You are free to create as many of them as you please. The restriction applies only at setup.
Moslem coloration: Yep, I have noticed that Mamluks and Ayyubids both are dark blue and Zenata and Bukhara are both light blue. I think I could change Mamluks and Zenata to something else, as they are the uncoolest names of the bunch.
Basque de la Vega: Hmh, could this guy's surname be changed at some point? Duke of Almeria is a de la Vega... Though it's not a big issue having two different guys with same surname, it could be more interesting to have many different surnames.
Archbishops after game start: You are free to create as many of them as you please. The restriction applies only at setup.
Moslem coloration: Yep, I have noticed that Mamluks and Ayyubids both are dark blue and Zenata and Bukhara are both light blue. I think I could change Mamluks and Zenata to something else, as they are the uncoolest names of the bunch.
Basque de la Vega: Hmh, could this guy's surname be changed at some point? Duke of Almeria is a de la Vega... Though it's not a big issue having two different guys with same surname, it could be more interesting to have many different surnames.