bulbs keep burning out, tripping circuit breaker
Look for light bulbs that are rated for 230-400 volts.  By which I mean LED, the only technology worth spending money on in this day and age. They use electronic switching power supplies, which chop line voltage into a much lower voltage.  By nature they can take a variety of voltages.  You just need one that's built well enough to take 400V.  

If your expensive electronics are multi-voltage, but can't handle 400V, then I would get a heavy step-down transformer, and configure it for 230V in, and 120V out.  When the system faults toward 400V, the "120V" side will increase in proportion, but it won't go above 240V.  

Losing neutral

What's happening is you are losing the "neutral" wire and the it's floating around, depending on the various loads on each leg. More loads pull the neutral toward that leg's extreme.   

Euro power is 3 phase "Y" (3 legs with neutral in the middle) and your apartment gets 1 or 2 legs.  If you remember enough high school geometry to draw a 120 degree Y shape with 230V legs, connect the corners and you get a triangle with 400V on a side.  The corners are fixed and the neutral is being dragged around inside that triangle, making your power go higher or lower depending on which corner you are at.  

That is not normal.   The Hungarians who say that it is -- do they live in your same building?   If so, it's a problem with the building neutral and the landlord oughta just fix it.  If it's in the same city or region, then the power company is terrible.