A couple immediately come to mind.
Beware cheating units away from Paris. If you attack South France, you’d better add some aircraft to the attack of Paris to make sure you’re not taking unacceptable losses there. It is not good when you start losing mech, and unthinkable to be losing tanks. That can start happening when you cheat 2 or 3 ground units away from Paris and don’t replace with air.
Second, Russia. If you’re building fleet in the Med as Germany early, you’re not pouring the heat on Russia and any good player will make you pay. It is a common thought of players relatively new to the game that they need to get Italy going, but after a lot of experience, I can tell you that Italy is highly over-rated.
There are two keys to this game. Russia, and China. How those two powers are doing matters more than any other - the rest are sideshows, and only really important as to how they affect Russia and China.
From both of your posts, I’m starting to wonder if you are too fixated on Italy. Italy is a minor power. Even when she gets going and has maybe 40 income, Italy tends to underwhelm. Italy should be hit in the mouth in the very early going, and the Allies can always shut Italy down if they really want to. A lot of times, they don’t even need to.