Continuing the discussion from Watch Adam Savage build Chewbacca's bandolier:
I think my personal pronunciation has been closer to kash-YEE-ick
But I think the canonical pronunciation (from the third of the movies-that-don’t-exist) is just ka-SHEEK (/kəˈʃik/).
One of the things that bugged me about those (wholly imaginary) prequels was the infantilization of the fictitious names of new planets and characters. Older, established names from the original trilogy and EU seemed evocative and quasi-exotic, like Tatooine, Dagobah, Coruscant, Corellia, Ord Mantell, Yavin, Kashyyyk… They all sounded like places from the Golden Age of Science Fiction without being too pulpy. Same with character names like Obi-wan Kenobi, Darth Vader, Leia Organa, Bossk, Boba Fett, Generals Rieekan, Dodonna, Madine, Veers, and Tagge, even Tarkin and Skywalker seem to perfectly walk the line between realistically mundane and wonderfully imaginative.
And then… the prequels. Naboo. Plo Koon. Dexter Jettster. Jar Jar Binks. Count Dooku. Kit Fisto. Darth Sidious. Poggle the Lesser. General Grievous. Theed. Boss Nass. Nute Gunray. Kamino. Mustafar.
Bleah. They all sound like they were toys first.