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Thanks!
In my group I have also allowed "writing" to be a valid specialisation. I did have Latin in school vor six years. By the end I could translate Latin poems but were unable to use even basic conversation as we never spoke but only wrote Latin. Thus I think it possible for a magus to write Latin better than he could ever speak it.
Another thing that new players schould not choose as virtue is Diedne Magic. With just one exception: Someone who easily learns all the chapter about magic by heart. Otherwise he eiteher never uses his virtue or the game becomes incredibly slowly for one character is always looking up almost any action he wants to do.