Blaze

No. Though it clearly departed its location, it never 'stops,' which is what causes the flame to cause damage. To 'stop,' a unit needs to move first. (Note that if the Blazing unit somehow died while moving, then Blaze would in fact deal damage when the unit died.)

Yes. The source of the damage is the Blaze spell, not the unit.

No, since the Megamoeba still occupies the sites and thus never departed.