Thanks for the replies.
A few thoughts:
I have worked in Marketing and in Education - both are riddled with jargon, which I divide into two types:
There is the jargon which is 'exclusive' nonsense without which you'de be lucky to get through a job interview.
There is also jargon which is a commonly understood and highly specific vocabulary. This is also bound up with the language in which we choose to express it. I understand airline pilots all use English when communicating and that doctors and botanists use Latin.
Doctors also have a hilarious set of acronyms as well, which they write on people's notes for other medics to understand like 'AWFB' - Angel Waiting at Foot of Bed, or 'LONH' - Lights On but Nobody Home'.
Whatever I am involved in, for example martial arts, I tend to seek out the oldest and hopefully 'purest' exisiting source for it. So I'll practice a modern art like Aikido but also seek out ancient Ryu for swordsmanship or unarmed techniques. However, although I am interested, I don't go even further back to the Chinese arts or the origin of many, Kalari from India.
I'm the same with languages. Although I chant it a lot, I am not a fan of the Tibetan pronunciation and try to seek out Sanskrit mantras etc. I must admit, though, I get completely lost with scrupture that has possibly first been written in Pali, Chinese, etc. or in a language predating consistent use of Sanskrit. It's tough enough to be taught in English by a Tibetan who is translating from Sanskrit.
I think the best way for Buddhists to share understanding is through a commonly shared jargon, a precise shorthand.
I think integrating some of the terms into our everyday (English) language creates familiarity, but we must also guard against corruption - 'karma' as 'fate' for example, as if it is all in God's hands whether our autorickshaw hits the Tata truck.
Although I doubt that we will ever get all the schools and scholars to agree on every aspect of terminology, it is still very useful IMHO to have a jargon for Buddhadharma in the sense of a specialised vocabulary. Mind, you, some teachers seem to latch onto a few key words and repeat them again and again. The teachers of one sect all use 'impute' and 'bliss' and 'Geshe-la says' dozens of times in each class and it really does grate after a while, I agree. I guess it is a very valuable part of the transaltor's role to avoid words with a very different traditional cultural coinage but these things do settle into new host cultures, as did Christian vocabulary.