Firebrand overall was a very fun spec to play, most of my experience came from WvW fights and I feel like the Tome system needs an urgent rework.
My suggestion for the overhaul would be to
1) Change the tome activation to something like that of an engi kit. Make it so you cant be interrupted.
(In the current state its slow to get to the skills you want and one example is being interrupted puts it on full cool down a thief stealing on you while trying to use courage gives you a 70 second cooldown)
2) Overhaul the page system per tome to a shared ammo system, make the standard amount of pages you have 8 and rework the trait that gives 8 to a faster cooldown per page. This gives the player a choice on where to spend their pages in a fight they can allocate them to Damage, Healing or Support, this coupled with the instant cast if the tomes are switched to be like kits stops them being overpowered and abusable.
Another possibility would be to make each tome have their own ammo timer but a slow regen time on it.
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