The problem is that 2.b. is blatantly false.
Nope. Felling bad about bad things only helps you to protest or punish people (yourself included) for the way things are. This is a very indirect form of "fighting bad things", and one which is largely ineffectual outside our evolutionary social environment. In the modern environment, protest and punishment are next to useless for accomplishing anything.
Do you really believe that someone who felt happy despite knowing about the state of suffering in the world would be more strongly motivated to reduce suffering than someone who felt a great sadness and a burning desire to stop it every time they thought about it?
You're begging the question here: what is the difference between "strongly motivated" and "burning desire"?
That is, you just said, "I think that there is more M in S+M than there is in X", where you haven't expanded X.
(Also, I'm not sure what kind of brain can actually experience "great sadness" and "burning desire" at the same time. Mixed emotions are usually not extreme emotions.)
It might be more useful to restate your question as "Will an otherwise-happy person have a greater probability of increased utility per their values, than one who is sad about the world's currently low utility?" My answer to that is an unqualified YES. Happy people make better choices about which actions to take, have greater motivation to act upon them, and better follow-through -- it is simply no contest.
if your moral system dictates, as most of ours do, that reducing suffering is currently by far the best thing you could do, and you actually want, unlike most of us, to follow your morals to their conclusions
Let us draw an important distinction between "morals" and "values". To me, a "moral" is a statement about what levels of a value we should protest or punish (e.g. by shaming/shunning), and it is of limited use outside the evolutionary environment (where others shared our morals and could be more influenced by our social maneuvering).
As Asimov put it, "never let your sense of morals keep you from doing what is right." The people who put a lot of moral weight (using my reduction of "moral") on the elimination of suffering seem much more motivated to protest, "raise awareness", "speak out", and perform other social signaling behaviors in place of direct action.
OTOH, I know lots of happy entrepreneurs who give or volunteer on behalf of various causes who, AFAICT, are not at all outraged or depressed by the suffering they witness. Without exception, the people I've met who actually DO things about the problems of the world (as opposed to merely talking about them) are happy people who are not disturbed by suffering in principle, even if they may be moved in relation to some particular individual's suffering.
So, in the context of this post, what is being said is that dropping one's moral rules allows one to pursue one's real values without impediment by our biased instincts to protest-and-punish -- which are in any case mostly ineffectual in the modern environment.
I wholeheartedly agree.
Related to: I'm Scared; Purchase utilons and fuzzies separately
Expanded from this comment.
You have awakened as a rationalist, discarded your false beliefs, and updated on new evidence. You understand the dangers of UFAI, you do not look away from death or justify it. You realize your own weakness, and the Vast space of possible failures.
And understanding all this, you feel bad about it. Very bad, in fact. You are afraid of the dangers of the future, and you are horrified by the huge amounts of suffering. You have shut up and calculated, and the calculation output that you should feel 3^^^3 times as bad as over a stubbed toe. And a stubbed toe can be pretty bad.
But this reaction of yours is not rational. You should consider the options of choosing not to feel bad about bad things happening, and choosing to feel good no matter what.
Your bad feelings, whether of fear, empathetic suffering, or something else, are probably counterproductive. Not only do you feel bad - a loss of utility in itself - but such feelings probably hurt, rather than help, your efforts to change the world for the better.
You may believe that your emotional outlook must be "rational": that it must correspond to your conscious estimates of the present or the future. Perhaps you expect to die of old age, or perhaps you are aware of people being tortured in secret prisons. You are forcing your emotions to match the future you foresee, and so you feel unhappy and afraid.
I suggest that you allow your emotions to become disconnected from your conscious long-term predictions. Stop trying to force yourself to be unhappy because you predict bad things. Say to yourself: I choose to be happy and unafraid no matter what I predict!
Emotions are not a a tool like rational thought, which you have to use in a way that corresponds to the real world. You can use them in any way you like. It's rational to feel happy about a bleak future, because feeling happy is a good thing and there is no point in feeling unhappy!
Being happy or not, afraid or not, does not have to be determined by your conscious outlook. The only things that force your mind to be unhappy are things like pain, hunger, loneliness, and the immediate expectation of these. If you accept that your goal is to be happy and unafraid as a fact independent of the future you foresee, you can find various techniques to achieve this.
Unfortunately such techniques vary for different people. This post doesn't discuss any: it is about the prerequisite decision to be happy.
Expecting to die of cancer in fifty years does not, in itself, cause negative emotions like fear. Imagining the death in your mind, and dwelling on it, does cause fear. In the first place, avoid thinking about any future problem that you are not doing anything about.
Use your natural defensive mechanisms, such as of not acknowledging unsolved problems, or compartmentalizing different beliefs. Don't dismiss them as biases or irrational practices. They exist for a good reason and have their proper use.
This does not mean that you should ignore problems on the conscious level. It is possible to decouple the two things, with practice. You can take long-term strategic actions (donate to SIAI, research immortality) without acutely fearing the result of failure by not imagining that result.
When you're faced with something terrible and you're not doing anything about it anyway, just look away. Defeat the implicit LW conditioning that tells you looking away from the suffering of others is wrong. It's wrong only if it affects your actions, not your emotions.