Your objection against NAE is also raised by MichaelStJules in this post, which I have responded to. I completely accept NAE.

Rejecting transitivity is vulnerable to money pump arguments. So I completely accept transitivity.

I would reject mere addition. Mere addition implies that it would be moral to create someone if they experienced a year of extreme torture followed by just enough happiness to 'outweigh' the torture.

Re 2: Your objection to non-anti egalitarianism can easily be chalked up to scope neglect.

World A - One person with an excellent life plus 999,999 people with neutral lives.

World B - 1,000,000 people with just above neutral lives.

Let's use the veil of ignorance.

Would you prefer a 100% chance of a just above neutral life or a 1 in a million chance of an excellent life with a 99.9999% chance of a neutral life? I would definitely prefer the former.

Here is an alternative argument. 

Surely, it would be moral to decrease the wellbeing of a happy person from +1000 to +999 to make 1,000 neutral people 1 unit better off; rejecting this is outrageously implausible. 

If the process was repeated 1000 times, then it would be moral to bring a happy person down to neutrality to make a million neutral people 1 unit better off.