Yup, Olorin is Gandalf. And Mithrandir, and Lathspell, and Tolkien really loved multi-name characters.

Don't sweat the accents, I say. (You'll note I hardly ever type them, in part because most online environments don't support all the special char code thingies.) Mostly, I use them as a general guide to emphasis, but Tolkien's poetry is strictly rhythmic, so the poems can give good pronunciation cues too.