Has Edward XIII had a child yet or is Elizabeth his heir?A certain future chapter will explain why he thought he had a shot, but Umberto believed the army would unconditionally stand by him as he was the First Marshal of the Empire, a title only him and the Duce can hold and there was no Duce at the time.
Ciano used to be the top dog inside the party, its hard to let go of that arrogance, it was still unlikely that Grandi would have won once the news that Messe was made Prime Minister reached the council.
Graziani, if he had died, joined, or simply gone back to sleep, could have prevented the counter coup against Umberto. He was the most respected Marshal and Chief of Staff, he held a strong sway over Army units which did not know which side they were supposed to pick.
Had Balbo's plane not crashed then he would have been present at the council and Grandi's power play would not have even started, Balbo had far more support in the army, people, air force and in the party than the other contestants. If Umberto still went ahead to strike the council that night then the Fascists would have been able to rally support faster and maybe even provoke a stronger popular reaction. Umberto II is not a prestigious and relatively popular War Hero like his father was.
Almirante was considered a radical for the standards of our world, in here he is a moderate due to the Overton window. He would not oppose the Monarchy in Bulgaria or Croatia, as they are pro-Italian in general. Although only God knows how long a man speaking of fighting corruption can last in Italy.