I am interested in your project. I don’t actually have any pet peeves as regards grammatical mistakes. My pet peeves relate to spoken language, in particular, when someone is giving a speech and the first thing they say is “Um.”
My inclination would be to treat students’ write-ups much as I would my regular editing work, i.e. providing a tracked copy, with comments where required, but in this case, adding extra comments at the end to highlight common errors.
I registered with Freelancer more than two years ago and have 180 reviews, all positive. English is my first language and my skills include technical writing, editing, proofreading, and transcribing. I have proofread/edited a variety of academic papers across a wide range of subjects for Freelancer clients.
In addition, for nearly two years I have been the copy editor for the International Journal of Wellbeing, an online journal, as well as the copy editor for the Blind Foundation of New Zealand.
For two years I was a copy editor for Elsevier Science Publishers in Amsterdam, the Netherlands (during the time I lived there), rewriting text by authors who were not native English speakers.
Having been a teacher of English in high school for four years, I have spent many hours making corrections and suggestions for students' essays. For an additional two years I was a teacher of English as a second language.
For six years I was a member of a writing critique group, regularly reviewing the stories submitted.