On 1, I believe you're begging the question on the is-ought divide, which is the point of contention with Sam.
On 2, my recollection is that Sam basically excommunicates psychopaths from the human race. They don't count. In the end, I don't think that particularly helps him, as he'll have to excommunicate anyone who isn't a universalist altruist, and not just for humans, but for all conscious creatures.
On 3, I believe you're mistaken. The usual rubric Sam's utilitarianism goes by in the circles of Sam is WBCC, Well Being of Conscious Creatures. He grants that other creatures can be conscious, that there are degrees of consciousness, and that their well being counts in proportion to their degree of consciousness.
On 4, Sam is at least consistent, in that he'll argue that punishment for criminals is an icky leftover of our primate evolution, and fundamentally an evil in that it doesn't maximize WBCC, which is the standard by which Good is measured. The objective morality that Sam believes in is not the morality that people objectively have.
Disclaimer- I only went from his responses to critics, in which some points weren't clear.
1: I just assumed (perhaps wrongly) that even Sam Harris would see the validity of an is-ought divide to some extent. If he hasn't, then I can refer to Hume and copy-paste his arguments for the win.
2: O.K then.
3: Refer to my disclaimer.
4: Which makes it even harder for him to go from an is to an ought, as he can't use the idea that he's merely following human intuitions somehow. He's following his own, very alien intuitions instead and can't justify them.
Sam Harris is here offering a substantial amount of money to anyone who can show a flaw in the philosophy of 'The Moral Landscape' in 1000 word or less, or at least the best attempt.
http://www.samharris.org/blog/item/the-moral-landscape-challenge1
Up to $20,000 is on offer, although that's only if you change his mind. Whilst we know that this is very difficult, note how few people offer large sums of money for the privelage of being disproven.
In case anyone does win, I will remind you that this site is created and maintained by people who work at MIRI and CFAR, which rely on outside donations, and with whom I am not affiliated.
Note: Is this misplaced in Discussion? I imagine that it could be easily overlooked in an open thread by the sorts of people who would be able to use this information well?