It is like Serbs don't know how to live with other nations?

I think, given recent history, that that is evident. Serbs & Albanians live together under an independent Kosovo. It is Serbia who goes around bribing microstates in rescinding their recognition of Kosovo, trying to block Kosovo from Interpol, etc etc.

So my question remains: how would Serbs go at this without trying to re-do past mistakes.

Unless you see "living peacefully" as cutting your losses and moving on; something which the collective Serb psyche doesn't seem keen on doing. I think that giving up this alt-history of Kosovo belonging to Serbia because of emotional reasons is a first step.