Abstractions and Translation

Interesting thoughts. Language is indeed interpreted syntax, and requires an interpreter or else it's just non-random arrangements of matter.

"If communication is just translation, how much meaning is lost in the process?"

I don't think it's 'just' translation. It includes it, but translation is a form of interpretation that doesn't move between layers of abstractions and instead moves laterally along the same "plane of abstraction" to another syntax/encoding... which can literally be called "translation" (like in vector space movement), and could even possibly be the same mathematically speaking. Therefore, in theory, translation can be lossy or isomorphic (not losing any information), and the latter means that you can go back to where you started from because you have all the information still there.

"If language is the tool with which we represent abstractions, what does a richer language (rich in terms of how much information it can represent) than what we currently have look like?"

That Sci-fi movie, Arrival (circa 2017) is about this. I don't want to give any details, but it's pretty good if you're into atmospheric sci-fi's.