I personally don't know Hanja at all, and I think that's common for most younger Koreans. Korean did borrow from Chinese characters historically, but it's similar to how English was influenced by Dutch, German, French, and Latin — each language developed independently.
Korean has its own pure Korean words (순우리말) as its foundation, and borrowed some Chinese-origin vocabulary on top of that.
Hangul was specifically created so people wouldn't need to learn Chinese characters.
So Han's keywords use native Korean words where possible — it fits the spirit of Hangul itself.
Yes, but there is a potential for increased expressibility with Chinese characters which I've always found evocative and beautiful --- perhaps if there is some keyword which is long/awkward a character might be a better fit? Or would it work for a user to choose Chinese characters for module names? But also yes, I'm an old-fashioned sort of person as my kids are constantly pointing out, and moreover, it's not like I ever did much of anything w/ the 500 characters which I memorized after my graduation proficiency test (pulled them out for a couple of projects in college...)
\begin{quotation}
\emph{The beginning of wisdom is to call things by their right names.}
--- \textsc{Confucius}
\end{quotation}
Very glad /u/faitswulff mentioned Wenyan (though I'm bummed that there are only simplified Chinese and Japanese translations).