If a 50% male Italian mates with a 50% female Italian, what's the offspring?

Depends on the nationality shown on the baby's birth certificate.

A 100 % 50% Italian child

I know this isn't just about math so to answer the first question the kid would be half Italian and the other half would be a mix of whatever else the parents were.

If you don't want to do the math do this..

On a peice of paper make a box. divide that box into 4 squares. On the top of the first box write an I(for Italian) over the second box write O (for other) Down the left hand side net to the top box write (I)talian bottom box write (O)ther. Now in the first top box write I. this represents the (I)talian on the left hand side. Write another I to represent the (I)talian above. Next box will be I O. First bottom box will be O I and last box will be O O. Now count the I's each I counts for 12.5% of that persons total genetic inheritance. You have 4 I's if you did it correctly. 12.5 x 4 = 50.

Just 50% Italian babies.

They would be 50% because lets say you are german italian and your wife is french italian if you pass all of that to the child it would then have 1/4 german 1/4 french 1/4 italian and another 1/4 italian to make 1/2 italian.