It seems to me that most moral questions can be reframed to be questions about net benefits and costs of our actions. Collective morality looks at the net impact of an action on the social group. Individual morality looks at the net impact on oneself as well as the group .
In your question 1, consider the statement, "Net human welfare will be improved if we avoid a repeat of World War II." This is a factual statement which arguably carries the message of the "ought" version.
For question 2, death is a very deep and strong moral (or ethical) rule. Consider some that are not so strong, like the rule, "Giving to poor beggars on the street is good." You can probably imagine reversing your belief on this moral issue. Doesn't it largely come down to the net benefit of your actions?
Question 3, standing on a chair makes no one any worse, but stealing from a backpack causes harm.
Question 4, I would predict that achieving a greater understanding of the impact of one's actions, positive or negative, might cause them to be viewed in a new moral light. In terms of discoveries vs decisions, perhaps discoveries happen when a new understanding makes it clear that the net impact of some action is good or bad; and decisions would occur where the net effects are less clear, and we have to choose whether to err on the side of caution.
For questions 5-7, again I think the example of human deaths is not the best choice for working on these issues. It is so strong and absolute. Plus, in the framework I am proposing of net benefit, death is something of a special case since dead people no longer experience anything. In some ways one might as well ask about the impact of our actions on unborn or hypothetical individuals. I think if you change the examples to less extreme questions like the one I gave, giving to the poor, these questions are easier to make progress on.
Well, this is getting a bit long...
My intended next OB post will, in passing, distinguish between moral judgments and factual beliefs. Several times before, this has sparked a debate about the nature of morality. (E.g., Believing in Todd.) Such debates often repeat themselves, reinvent the wheel each time, start all over from previous arguments. To avoid this, I suggest consolidating the debate. Whenever someone feels tempted to start a debate about the nature of morality in the comments thread of another post, the comment should be made to this post, instead, with an appropriate link to the article commented upon. Otherwise it does tend to take over discussions like kudzu. (This isn't the first blog/list where I've seen it happen.)
I'll start the ball rolling with ten points to ponder about the nature of morality...