Ackchooly nobody knows how her name was pronounced just as nobody knows how it was actually spelt as the Celts didn't have a written language. What we have is what the Romans called her in their written accounts. The fads and fashions of pronunciation have indeed changed over the years and will, no doubt, continue so to do. SWWLTBO is a Latin speaker and teacher .... she teaches that Latin should be pronounced as it is written as no-one has ever heard a real Roman speak she claims we can do nothing else. The arguments about Boadicea seem to me to have started with that pretentious twat Melvin Bragg and his ilk. I notice that Stephen Fry straddles the fence by using both whenever her name crops up on QI but then he straddles the fence on many things. Prolly the best answer.
The Paree as opposed to Paris largely depends on whether you want a Frenchy to understand you. In France I do try to use a French accent that the locals will understand but that largely depends on which part of France you are in. At home I am firmly of the Paris school.