I agree with your point number 2 (except I think you should say NP hard instead of NP since many NP problems have efficient algorithms), in fact I've made it be

I agree with your point number 2 (except I think you should say NP hard instead of NP since many NP problems have efficient algorithms), in fact I've made it before. While it may be reeasonable to believe that technology will eventually lead to implementations of intelligence that are significantly faster than biological ones, this doesn't necessarily mean there will be a huge qualitative difference (say, to the point of humans being totally incapable of understanding an AI's actions, as some suggest) because the "intelligence problem" may be dominated by exponential growth in complexity of the search space as one attempts to consider more alternative paths. I do think that the question of the "safety" of AI is something that needs to be seriously taken into account by anyone realistically contemplating the development of an AGI but I also tend to think that some of the concerns expressed by prominent individuals are a bit overblown and don't take into account the range of safeguards that could, should and most likely would be put in place by any group realistically capable of solving the extremely hard problem of general intelligence.