Weapons are important, yes. You can also get decent weapons from Shiva and Leviathan.

As a new tank, I'd like to pick the brains of people more experienced than I -- I noticed he does Flash, CoS, then Flash again, followed by RoH cycling.

Why does he do Flash again after the CoS? Is it better to do RoH --> Flash ---> RoH ---> Flash cycling once the fight starts going underway, and Provoke + Shield Lob if aggro is lost?