Romanian government giving EU passports to serbs who identify as Romanian

It's a great thing for individuals who get more opportunities in life. Hard to claim it's directly damaging to Serbia either, although it is vaguely, potentially unsettling. In practice, it doesn't cost us anything, and there might even be benefits to Serbia through remittances. Once we're in the EU, it won't matter at all.

Romanian orthodox church is stepping over agreed geographical boundaries...

Roughly the same stuff that SPC is doing (notably in Macedonia), except that when our guys do it, it's all right and good. Orthodox churches are weird in that national borders are sort-of meant do be borders between churches, but not consistently, only when it suits the claims of a given church.

In all honesty, if our priests are fleecing families for funerals and Romanians are doing it for free, it's not the Romanians that I would complain about.

assimilated by the Romanian communist government

Nobody is defending the communists and Ceausescu, everybody suffered under that regime, in countless ways. It would be a bit insidious to pin what they did on Romanians as a whole.