As a Schengen citizen, you can get a triple entry Thai Tourist Visa for 2 months each stay in your home country. Once in Thailand, you can then extend each stay painlessly by one month for 1.900 THB at the local immigration, so you can stay 9 months total.
You have to leave the country by plane for at least 1 week each Visa run and there is no guarantee to get back in, especially the 3rd time. It’s easy to find a flat for 3 months in most Thai cities, in Chiang Mai even for 1 month. Just prepare for the worst on a Visa run.
As for the Education Visa, it doesn’t have to be Thai courses, people do English courses for example and class adherence is still not enforced.
Also learning some Thai will enrich your experience by a landslide, but I don’t wanna lecture you