Hello Catkin. You're right about 4 letters to be changed in column 6, causing a country to appear. I'm wondering, with your forensic analysis, where the crime was, but that's digressing. You're also right to focus on column 10 as the object of the instruction given by the first letters of normal clues. Maybe you're over-thinking this, and perhaps quite a few of us did. If you carefully work out the numbering, you'll see that the entry you refer to is 21 Down. If you write in 21 above the first letter, then you have '21 Letters'. Which is the number of letters in the Italian alphabet. Z is included unless you want to go without pizza. 8D, the entry above, doesn't need to be changed in any way.