I don’t agree with the altruism part in there. The whole process has nothing to do with altruism - which doesn’t exist at all. The least the vehicle gets from what feels like an altruistic action is a good feeling. Moreover the information in the vehicle is the same whether it is a parent or a child, therefore any action towards the other can’t be consider as form of altruism neither.
Thus said, the whole concept of development of spirit kinda falls apart. Our body does actions based on the information, but whether the information undergoes any form of upgrade, or the vehicle has to go through similar situations in the new vehicles cannot be said so easily.
Rule of thumb implies that the information from the information (sounds weird:D) is transmitted manually - from one vehicle to the other one.

Otherwise great article! If every christian tried to discuss the matter like you do. I only know handful believers like that...