It worked for this guy apparently:
http://www.svatopluk.com/xroads/linguist.html
But i doubt he managed to finish the main quest because one or two main quests require the player to kill someone. Something that needed a fix.
IIRC (this was about 13 years ago! haha) I think the main reason Magnus created the linguist was to have a class whose level you could directly control almost completely. Then he RP'd all that other stuff. The Linguist wasn't a pacifist.
You could keep probably Linguist at level one indefinitely. Generally, you'd need to use a trainer to increase any of the language skills. They would get a little bit of practice in regular adventuring. However that would be very rare if you had the languages of monsters a level one character would almost never encounter in primary/major.
eg.
Primary: Dragonish, Etiquette, Streetwise
Major: Daedric, Spriggan, Mercantile
Minor: other languages
This way you could be level one, yet have trained or increased through regular adventuring, and have whatever devastating skills (eg critical strike, magic) you wanted maxed out.
People scoffed when he posted that class but it is the most over-powered class. Ever!