Gotta repeat myself.true i guess
but kisame has a huge chakara pool soo even then he could get out
A lot of people could break Itachis finger genjutsu, being unbreakable is not why its so dangerous. The reason for that is fact, that one dont know that hes already uder genjutsu, until weird shit starts to happen. To put it simply, Itachi can use it to create himself an openings.