1. The A to the Q, "Is a teacher required to practice meditation?" is a categorical no.
Re-frame: Is a teacher required to successfully
That seems more appropriate to me.
2. It's not so much about a teacher requirement as a collaboration between the instructor and instructed to arrive at workable instructions.
3. I've observed several practitioners use the phrase "my teacher" in a way that suggests they're wearing it like a credential badge or a backstage pass, or as conferring the right to brag on them, which can devolve to: My
Ajahn can beat up your Ajahn!
4. I trust that if I meet someone that (a) I could humbly and with sincere respect refer to as my teacher, and (2) that is willing and able to handle
me, then I will probably at that point technically have a teacher. Until then, I will remain teacher-less.
PS: Can a BOOK be a teacher?