oh no please don not do this.
i see lots of "beginner mistakes"

do not route any tracks on the power planes. these planes are called power planes and not routing layers. by doing this, you distroy the benifits you get by using power planes.
again power planes, if handled by a good sw, do not allow you to route tracks on them.
now we come to split planes.
the main and only difference between power planes and split planes is, that a power plane has only one signal over the whole layer and a split plane is like having a power plane splitted into areas where each one is a power plane.

next point.

filling the outter layers with gnd does not make a lot of sense and is very dangerous, as by doing this you can place a lot of little antennae on these two layers. think twice and have an eye on these GND-fills. they need a good connection to the gnd plane. with good connection i mean a very good one from a hf/emc view.

regards

michael