A. "=" means that you should write on the right the answer to
the calculation on the left.
This is the same as the (mis) understanding that "=" means the
answer comes next.
No, this habit will produce the correct answer for arithmetic
problems, but will trip students up, and make it harder for them to
learn when they encounter pre-algebra and algebra topics in middle
school. One of the big goals in reforming elementary education is
to make the transition to algebra easier, so we need to learn ways to
correct this misunderstanding.