Hi,
Congrats on your new BP
Cage aggression really isn't a problem with ball pythons - in fact you are more likely to be bitten when moving a BP in feeding mode from his eating container back into his normal enclosure.
The main worry I have with your plans for a naturalistic environment are cleaning and vibrations from the pump.
I have no doubt it can be done though - it'll just be a lot harder to setup correctly and maintain.
How were you thinking of stopping the water turning the whole substrate into mud?
It's important to make sure the substrate is never kept wet as this can lead to scale rot as well as mould etc.
I would also say that for the first 30 days (and probably for a couple of months ) at least you will want to keep the enclosure simple to monitor for problems like mites, check out his poop looks normal and get him started on a good feeding regime.
I would keep everything as simple as possible during this period so paper towel or newspaper as a substrate, a small waterbowl and a nice, dark, tight fitting hide at each end of the temperature zone.
dr del