Hi there!
My name is Fernando, and I'm very interested in your project. I love reading books and analyzing them. Therefore, I would be more than happy to be assigned these tasks. I have experience writing articles in English (copy, content, product descriptions, etc.) and vast experience writing articles in Spanish related to the realm of law (I'm a lawyer). Moreover, I have a great deal of patience and a desire to engage in long-term work.
Regarding the pay rate, 18 USD per feedback sounds fine.
Looking forward to hearing from you,