Were the Istari Elves or not???

[Tinuviel of Denton]

Yes, Gandalf and Saruman were Istaris, weren't they? The Maiar were angelic beings in the form of an old man.

You'll have to pardon me, but I'm going to pick this sentence to pieces. Istari is the plural, Istar the singular. The Maiar could take any form that they so chose, not just that of old men. (ie, Melian, Arien, etc.)

Okay, now to get on topic.

The Istari were Maiar who wore the forms of old men. Not Elves.

Actually, I was under the impression, from a few of the things that Gandalf said that he was there specifically to oppose Sauron, and that was why he left at the end of the Third Age because his task was through.

And I think that this question is pretty well answered. Mostly not by me.