well I'm been firmly on the fence but since OP has been testifying I don't believe intruder theory one bit. Far too many improbables. Plus not accepting responsibility for the gun incidents is very damning - he is not going to tell any truth he perceives will him him.
But the outright deliberate shooting of Reeva also seems implausible. There is still oodles of reasonable doubt.
So yes I think anger, argument, lashing out, she wanted to leave, he was in arrogant rage, get the fuck out of my house, don't turn your back on me etc etc and he exploded in anger.
He has testified as to how he acts and doesn't think. Then he shot Reeva, via the door, all guns and anger and arrogance and drama. Someone up thread summarized this scenario very eloquently.
I think he will get NG to murder, guilty of culpable homicide, and a fairly lengthy sentence.
I hope the best thing that will come out of this whole sorry mess is a spotlight will be thrown onto SA jails, and conditions in them will be seriously improved as a result to OP being sentenced to jail time.