Regarding 4, there are a fair number of people here interested in complexity theory issues so it shouldn't be that hard to get people to judge that. Also note that I deliberately made the question more precise by listing three of the more plausible ways the result might be extended rather than just that it would be tightened. That helps make the question clear cut (if it were generalized to anything that could be reasonably construed as a tightening of his result I'd bump the probability up but it would be much trickier to judge the result.)