To me, as a non-native speaker, unfiltered means without the polite wording you use to sugarcoat a report that wouldn't be particularly flattering otherwise. Filtered or unfiltered, the core truth remain the same, it changes the light under wich it is shined.
Adulterated means it diverges from...
Honestly, her hiring process felt like "entry level job, 10 years of experience required": they test her cooking skills, even with an external consultant, and then they put her on cleaning duty...
Probably meant that being accepted in the advanced course means you already have the skill and the knowledge to graduate, but they will make you work hard nevertheless, since they are training the best of the best. Or maybe if you don't work hard enough they will drop you to a lower course, so...
"A" language? 😂 He made up more than 15 only for the elves!
The guy was a philologist and was inventing languages as a hobby way before he even started working on the legendarium.