I want to be able to Disable Ghosts

I think there is a way to do this in MCCC Settings. So definitely check out the basic settings, the population settings, tuner settings, and the occult settings. You can have it so that when sims die they immediately transform into an urn, force the game to cull all ghosts, and prevent ghosts from spawning in the first place.

You can also just delete the ghosts your sims are friends with using MCCC.

I don't really know how to get rid of the urns, though. I've used LMS Release all the Ghosts mod and it's great for releasing the ghosts, getting an urn for a ghost that doesn't have one, but it doesn't let you destroy an urn or tombstone which is annoying. The only way I've found to delete them is to either put them in the inventory of a sim you are going to delete or put them on a community lot and then replace the community lot. Although the urn needs to be "unowned" by your sim for that to work or it will just end up back in their inventory.