Learn Russian: Именно поэтому я здесь.

Поэтому means "therefore" or "that is why," and it introduces a result. Потому что means "because," and it introduces a reason. The English translation "That is exactly why" functions as a result here (meaning "for that reason"), so поэтому is the right choice.

What is the difference between именно and точно for the word "exactly"?

While точно means "exactly" in the sense of being accurate, precise, or correct, именно is used to emphasize and pinpoint a specific thing, person, or reason. Именно поэтому means "for this specific reason and no other."

Could we change the word order and say Я здесь именно поэтому?

Yes, Russian word order is very flexible! However, placing именно поэтому at the very beginning of the sentence puts the strongest possible focus on the reason, which perfectly matches the dramatic emphasis of "That is EXACTLY why" in English.