Since I'm back from using Oolite and don't know if you can manually delete/install OXPs outside this (for me newfangled ) automagic OXP installer I'm not sure this works, but:
It does.. inside my /home/diziet/GNUstep/Library/ApplicationSupport/Oolite/ManagedAddOns folder, I've added another folder called Disabled OXZs. Any OXZs moved to that folder are not loaded by Oolite.
Most games have some sort of paddling-pool-and-water-wings beginning to ease you in: Oolite takes the rather more Darwinian approach of heaving you straight into the ocean, often with a brick or two in your pockets for luck. ~ Disembodied