Qwert makes a good point about the historical friendship of Hungarian and Pole. An enlarged Poland, possibly reviving the Polish-Lithuanion union, should be one of our long term foreign policy goals, as it would do much to secure our borders.
Additionally, we should view it on our interest to keep the Ottomans strong, as a fellow turanic peoples, and a strong regional power we can rely on, along with Bulgaria.
Politically, the National party should (reluctantly) form a coalition with the Imperial party at present levels of support indicated by the graph. Independence from the Habsburgs is a central goal, but we cannot allow the Kingdom to fall to Socialism or the minorities to foment rebellion. If we do not have enough electorate support to break away from the Monarchy, a personal union would be an acceptable compromise.
Now, to Kovan's questions-
1) A personal union is an acceptable compromise in this situation. It allows us nominal freedom, and the monarch can be deposed when german attention is elsewhere. Germany is an ailing state, and can not -always- be breathing down our neck. But we cannot try and resist Germany and Austria simultaneously, at least not initially.
2) Centralisation and Federation are both infringements upon Hungarian independence, and must be manfully resisted. We must build up our domestic army, but I think there is little to fear from the Austrian military. Our long term goal should not be annexation of Austrian or Bohemian lands, however- we do not want to become overextended, minorities in our own, such as befell the Austrians themselves. Friendly and independent governments in each area should be our goal.
3) Assuming our foreign policy had suffered such disasterous reverses as the destruction of Bulgaria, war with the belgrade pact nations would be the kneejerk reaction, to restore Bulgarian independence and destroy the rogue nations which destabilise the region. In the short term, Magyarisation must continue. Let them speak Hungarian in the workplace, and eliminate all notions of being 'seperate' peoples. Once Romania has been crushed, we could create a puppet government there for our noisiest nationalists in transylvania to migrate to, to secure our hold in the szekely lands.
The Serbian minority is small enough to ignore, and the Slovakian minority is too far removed from the front to cause us serious problems.