Yes, I can be a teacher without TEM-8. I'm not an English major, and I'm not a TEM-8 student, but there are many people teaching English.

In this society, as long as you are good at English and confident enough, you don't have to worry about not being an English teacher.

Similarly, in the translation industry, TEM-8 is not necessary. Having TEM-8 doesn't mean that your translation ability will pass.