With reference to the Ebb and Flow lunar satellites, was there any data about its geology? Is there a central core, or is it homogenous?
We know a considerable amount about the moon, but the picture is not complete. There are considerable resources available and so much data available that it would take too long to list every aspect of it, so instead the following are examples of resources (with annotations):
Our knowledge of lunar geology comes from the results of direct sampling (from rocks brought back) and orbiting satellite observations. Also, with inferences and comparisons with the Earth.
NASA's Lunar Geology page, this page approaches lunar geology by focussing on the 2 main sub-branches, the geochemistry and geophysics of the moon.
The geochemistry focuses on the crustal composition, volcanic petrology and the existence of polar ice, hydrogen and helium. The geophysics focuses on the crustal magnetism, moonquakes, outgassing, crustal features.
Both of which help scientists develop a picture of the geological history and the geological structure of the moon. Exploration of the moon's geological features in comparisons with Earth, are described as described in the online chapter Geology of the Moon as a geological 'Rosetta Stone'.
In terms of the internal structure of the moon, observations from direct sampling, sensors on the lunar surface and from satellite data have built up a reasonable picture of what the internal geology of the moon looks like.
According to the NASA page NASA Research Team Reveals Moon Has Earth-Like Core, re-analysis of Apollo mission seismic data has revealed that there are several similarities between the lunar and Earth internal structure (as seen below):
Caption from NASA: An artist's rendering of the lunar core as identified in new findings by a NASA-led research team. (NASA/MSFC/Renee Weber)
As can be seen in the diagram (and explained in all the links), the moon's internal structure is thermochemically layered, broadly similar to Earth (there are considerable differences). But the main point, in answer to your main question, the interior of the moon is not homogenous, but layered with a central core.
We actually know a number of elements present on the lunar surface including oxygen, silicon, iron, magnesium, calcium, aluminium, manganese and titanium. We have also observed that carbon and nitrogen have deposited over time from solar wind.