The pronunciation is slightly off in this exercise and several others containing the verb "venio". The first 'e' in "veniunt" should be a short vowel. Likewise, note the word "(ab) Ītaliā"; the first vowel should be long and the second short. Also make sure to say "pŭeri" without a long 'u'. Thank you!
The first "i" in "Italia" is more correctly pronounced short (though it is lengthened in dactylic poetry for the sake of fitting the metre).
Otherwise, your points are correct, and it is a shame that the readers have not made the effort to observe correct vowel quantities, especially given that these are not being marked with macra in the writing.
Is "a Germania" / "ab Italia" just a difference between the word starting with a vowel or not?