Huh. I had no idea the 't' was silent in Voldemort. Silliness.
Winston Churchill is supposed to have said, "It is the inalienable right of every Englishman to pronounce foreign words exactly as he pleases."
I think that's doubly true when it's a made-up foreign word in a made-up foreign land.
If you really want us to pronounce the word right you need to make it clear -- like having someone mispronounce it and get corrected. (Almost as cliche as having your protagonist look in the mirror and describe himself, but it does work.)
It usually doesn't matter.
It's neat that "Egwene al'Vere" can be pronounced almost exactly like Guenivere, but it's hardly essential to the story.
Kvothe sounding like Quoth (as in "Quoth the Raven, 'Nevermore'.") might be important.