“Was he unable to express his Torah without reference to literature?”
If you have to even ask that question you are clearly unfamiliar with his work.
“Or did he not care if people were able to understand it?”
His students were well-educated and he spoke in language that they could understand.
I’m a bit confused. First you seemingly take me to task for not being familiar with his works, but then you say that he spoke in a language that only his students could understand.
Also, for the record, his students were not well educated in literature. I’m friends with many alumni (alumnuses? alumnosouruses?) of Gush and they know less secular literature than I do.