With regards to your third point, there is a third optimization target you're not considering: E[(other two factors for relatives) • (probability said relative

With regards to your third point, there is a third optimization target you're not considering: E[(other two factors for relatives) • (probability said relative shares the given gene)] - hence humans not doing immediately after ceasing to be fertile, tending to care more about their kinship groups, and possibly also explaining genetic factors in homosexuality (since they may have handy side effects when it comes to capability to help out relatives).