NO summer income or ability to plan for Fall classes. Summer school courses are rare. Fall classes don't show up in the system until closer to August. Last year I picked up all of my classes the day before they started.
Starting teacher salary for "Full-time" teachers is roughly 5k less than the national average, and closer to 18k less than if you were to work in a brick and mortar school in HISD.
Classes are first come first serve. There is no guarantee that you can pick up enough classes to survive the year, let alone save for summer months. Unless you are certified in multiple subject areas, you will probably struggle.
Benefits are too expensive if you are considered part-time.
Remote, full-time, salaried corporate opportunities no longer exist.