The world is interesting. In the USA, we would have no problem filing an IFR flight plan from any airport to any airport.
Your takeoff into controlled airspace has to be coordinated with ATC , sometimes with a telephone call and specific times to be airborne .
Your landing approach to an airport without an instrument approach procedure has to allow for descent under vfr/vmc from min enroute or min vectoring altitudes.
Sometimes a controller will say: be advised that airport X has no instrument approach, say intentions. And you should be smart enough to say: request vectors at min vectoring altitude to a point three miles south of the airport and then plan visual approach upon reporting airport in sight.
But you are IFR all the way if you choose to be.
How are things in Budapest? How is the shop around the corner?