Yeah, pretty much. Though Naruto fails at explaining many things. Originally, Izanagi/Izanami was only supposed to be usable by someone who had the powers of both Uchiha and Senju (so Danzo with his arm made of Mokuton cells and the implanted Sharingan, and Obitobi with his Mokuton body and implanted left Sharingan [or his natural right eye, but he never used it that way]). Then Itachi just said "**** you, I'm Uchiha Itachi and I do what I want", and used it anyway -_-
That's one of my main issues with the series; it constantly spits on its own canon and changes it whenever it wants.
How many times can you actually use Izanagi / Izanami?
As many times as you have eyes to sacrifice for it. So typically, twice, and then you're blind. Danzo just managed to use Izanagi a bunch because he had the Sharing-arm.