carbon seat post to carbon seat tube - necessary to loosen periodically to prevent seizing in place?
A carbon seatpost will not freeze in a carbon tube much unlike metal to metal contact. So there is no need for the procedure you envisioned.

Using the carbon paste is highly recommended in your situation and also with metal/carbon contact. However you should never ever use any kind of grease or fat which might damage carbon components.

Consider investing in a torque wrench because it is near impossible to 'measure' the correct value with the wrist-o-meter. The recommended applicable torque is often printed on the clamp, like 3-5Nm. You should apply the lowest value first and increase the torque only of the post slips.