Well as I said before, Italy shot Germany in the foot that lead to Axis defeats years later and Hitler already knew this, that is why he began to reject Italian help whenever it was sent.
Look at it like this, Italy invaded Greece because Muso wanted to restore the Roman Empire hence his attack on Greece plus he just defeated two nations prior without help so in his mind, he thought Greece would be cake. Attacking Greece and being counter attacked by Greek/UK forces lead to the Wehrmacht being sent in to help the Italians which leads to Greek defeat. That lead to the pyrrhic victory that became Crete. Axis looked at paratroopers as being cancer and that lead to the Allies learning why paratroopers are useful which that bit the Axis in the A$$ in the end.
Of course as for Africa, I am sure Germany didn’t mind helping Italy because I figured Germany taking Egypt would cut of the UK navy from India as well as link Axis forces in the Middle East gaining oil reserves and possibly a secondary front against USSR. I don’t know if Germany would have the balls to attack India in this situation.
Obviously Germany had virtually no respect for the Italians. I think Rommel was the only one who spoke favorably about the Italian soldiers, hated their officers. After Italy surrendered and about half of the Italian military joined the Allies, Germany had no problem going from defending their allies to suddenly occupying a nation as well as engaging their former allies.