poynting vectors, are these true?

Question

1. electromagnetic wave direction: -y
momentary electromagnetic field direction: -x
then momentary magnetic field direction = -z
2. EM wave: +y
EM field: -x
M field= +z
3. EM wave: -y
EM field: +x
M field= +z

Answer 1

I always think of plane polarized waves as mixtures of pure states of RH and LH rotationally polarized photons. This seems to be more basic as this is the type of interaction that photons have with electrons.

Try analysing your problem to see what the time dependency is. This may be difficult and not answer your question in the end - but it is educative.