I am hoping someone can enlighten me with some answers regarding the family Sachsen-Coburg-Koháry
1. Did the monarchs of Portugal of the dynasty of Sajonia-Coburgo e Bragança maintained their position as titular heads of the Austro-Hungarian (Catholic) branch of the House of Wettin (Sachsen-Coburg und Gotha) also known as "Koháry"
The family of Sachsen-Coburg und Gotha (Koháry) in Austria is "independent", and has its own head (currently Prince Johannes Heinrich) but does not constitute its own house; it is in fact a branch of the House of Wettin (Guelphs). As far as I know until the death of D. Manuel II his rights in the Hungarian Magnates' House were deputised to their cousins who became the actual holders of the rights after 1932. The first one being Prince Peter.
2.Did the title of "Prince (German: Fürst/Hungarian: herceg) Koháry de Csábrág et Szitnya" pass down up to the present line after the death of Princess Mária Antónia?
The marriage agreement between Prince Ferdinand von Sachsen-Coburg-Saarfeld and Princess Mária Antónia does not mention anything in this regard, nonetheless several prominent historians name Prince Ferdinad as "founder" of the branch of "Sachsen-Coburg- Koháry". Wikipedia also mentions the princely title when writing about his heirs. Apparently none of these princes ever die in either Slowakia or Hungary, so I haven't been able to control which name they used in these countries.
Prince Ferdinand further became Hungarian subject of King Ferenc I (Kaiser Franz) when he was given the Crown lands that belonged to the Kohárys exclusively in the male line as a gift, but did his heirs continue to be Hungarian subjects? Prince Johannnes Heinrich, the present family head was born and has lived all his live in Tirol. Nevertheless his father Prince Rainer married twice to Hungarian ladies, lived and died in Hungary. I haven't been able to check which nationality he had when in Hungary but when he stayed in Vienna, he did give "German Empire" (Deutsches Reich) as citizenship to the City Hall. Did he own anything in present-day Slovakia?
3. Under which name were these princes enrolled in the Hungarian Magnates's House (Főrendiház)? Were they represented as Princes "Szász-Koburg-Gotha", "Koháry" or ”Szász-Koburg-Koháry?
4. Which properties in present-day Slovakia and Hungary belonged to Prince Rainer? The forum has discussed properties of the Bulgarian royals there, but nothing regarding Prince Rainer who was the titular head of the family? I wonder if after the collapse of the Empire any of these princes took up Czechslovakian citizenship? I mean Prince Ferdinand Philipp, Peter and Rainer.
5. Does anyone know if Slovakia has chosen to obey as well the so-called "Beneš Decrees"?