1. How would Itachi who's around 1.75 meter will be able to look into the eyes of a 10 meters (so to say) slug who has the eyes located rather to the upper sky than to the ground?
2. You keep putting words in my mouth. I said she can break out not that she's immune. Leaves her wide open from what? After the flesh comes the bone who is not that really easy to cut. The first slight of pain that she feels, she's out of genjutsu and can counter-attack. Even if not in the next instance of offensiveness while meantime she regenerates. This has been shown in the battle of the 3 Sannins. Again, failed argument.
3. Direct contact with the eyes. Why does it mean that Katsuyu has to do the same? If you put Tsunade in genjutsu, Katsuyu can disconnect her, if you put Katsuyu in genjutsu, Tsunade can disconnect her. See what I mean? Manda was by himself, Kyuubi at that time, as well.
4. Yes, Tsunade survived.
Uhm, excuse me, you call sloppy the best praised to be combatant style user in Narutovese who has been able to keep Byakugou an entire day plus around a part of the night WHILE healing and replenishing chakra of the other kages? The niece of Hashirama SENJU and Mito UZUMAKI?