Your Alfa motor mounts are designed to keep the engine and transmission in the appropriate position and also to isolate the rest of the chassis from vibration. The mounts support a great deal of weight, and are subjected to torque, heat and even stray gas and oil. All that stress causes the rubber to degrade rapidly. As the rubber softens, the position and stability of the engine-transmission unit is compromised. The photo shows the difference in angle between a new motor mount and a soft one.
Transmission mounts also suffer when the rubber ages and degrades. The photos show the difference between a good mount and one that needs to be replaced. A weak transmission mount allows the gearbox to drop in the rear, raising the front of the engine while binding the drive shaft.