You said:
"As the Mass increases, the volume to surface are ratio increases and so the thickness of an ocean on the surface decreases - water depth is given by (volume * small percentage)/surface area"
You meant:
As the Mass increases, the volume to surface are ratio increases and so the thickness of an ocean on the surface increases- ...

My other point was regarding a larger earth with a lower density- say a larger planet (if you want, as much as twice earth's diameter) with about the same iron core size as Earth has [not proportionally the same size].
From your post I quess it would be safe to say there wouldn't be more "water is sweated out of a planetary interior from chondritic material differentiating". But there might be more water from "water arrives from a "late cometary veneer" " assuming the cometary material added a significant amount of mass to the planet or perhaps maybe the planet would be hit more often since it's a larger target.