I wouldn't worry about excessive essay writing, but English is very important. There is no subject in the HSC more vital to law than English, even Legal Studies. This is for a number of reasons, including:
- the most obvious: law is expressed and passed on through language, recorded and written down for us to interpret and use; you need to be able to understand and wield that language effectively
- as Chief Justice Spigelman once commented, our adversarial system is "a manifestation of the power of Socratic dialogue" - and that entails the ability to communicate ideas to persuade and validate the truth using language
- there is not an excessive amount of reading however the difficulty of the reading is the most pertinent part: it can be very complicated, deep and verbose
- being articulate and clear are essential; two skills that you develop through a sound grasp of the English language
- advocacy might be said to be the art of persuassion. While you may not necessarily want to be a lawyer at the end of your degree, expressing your arguments in exams, assignments, and verbally in class participation and presentations all entails making use of the vast toolkit of words our language has to offer. Precision, clarity and semantic certainty go towards interpreting and applying the law.
Perhaps wait until you take on your electives or were you referring to exams? In my experience, law essays featured in every subject that I did both throughout the teaching period and also in the exams. My understanding was that law essays allowed students to analyse the policy and reasoning behind certain legal principles. 
