Replacing a shorted IGBT
1.- All I can say is that you had a large current that caused the fuse to melt, without any extra info that is all I can say. That current while it lasted could damage other stuff.

2.- You are calling it a diode, but those are both IGBTs, they require a signal to be controlled and have 3 terminals, unlike a diode that only has 2(among other differences) also specify the units of the reading you got, is that voltage?

3.- from the datasheet you showed, some components are not even diodes to begin with, the only way is to deeply understand how the circuit works and make sure every component is working well.