Alan,
You're right about the moon receding from the Earth - this is easily confirmed with laser ranging - but the current model of attractive-only gravitation cannot explain it.
Under that model the moon should spiral into the Earth [unless a force was acting on it to give it a velocity increase] and that is exactly what is happening.
By modelling the Math of Gravity on observations [instead of its quantum foundations] you model a NETT attractive force between large-scale Matter - in fact there are a number of forces including EM [as any nuclear scientist will tell you].
But to not acknowledge the presents (and effect) of the Earth's EM field on its own satellites is a bit like saying the Earth is flat [despite the evidence to the contrary].
A fully fledged quantum theory of Gravity must rely on a quantum foundation else it will need to be corrected every time better observations are made of the motion of planetary bodies as has historically been the case [Newton, Le Verrier, Einstein, Dark Matter].
I would argue [and will prove in Tetryonic QG] that your Dark matter halo can easily be replaced with the interactive, inverse forces generated by the Earth's own EM field, or at the least that this should be done before any other components like DM are considered.
Re- the mountains - I haven't given it much thought.
I do note that the Himalayas are made up of soft marine limestone that should have weathered as you say but it also had to form from a sea-level sedimentary deposit so it had to be transported up into their current location by some process over a relatively short period of time [another consideration for me to keep in mind].Attachment #1: Figure_70.05__Gravitational_Tidal_Forces_800x600.jpg