According to Gallup, 53% of people 18-40 (I'm 37) have children, and another 40% who don't want to.

Also according to Gallup and contrary to the implications in the original post, only 7% of all those aged 45+ with children would go back and not have children.

http://www.gallup.com/poll/164618/desire-children-norm.aspx

If "except for all the others" only includes those that have been tried, then I mostly agree.

The original wording of that quote indeed was "No one pretends that democracy is perfect or all-wise. Indeed, it has been said that democracy is the worst form of government except all those other forms that have been tried from time to time."

Typeo just above "Basal Ganglia" section.

For example infants are born with a simple versions of a fear response, with is later refined through reinforcement learning.

"with is later" should be "which is later"

The word "solution" has too much of engineering / hard sciences connotations for my liking.

Organising society is a process and the criteria of what can be considered a successful one are not stable on historic time scale unless you want to take the social darwinism approach.

It would take an enormously skilled tactician to win the vote by selling actually useful policies to a population that prefers simple rhetoric aligning with their color.

That presupposes that you have to win election by explaining the policies that you honestly want to enact. In reality that's not how modern representative democracy work. Neither how it works in practice nor how it works in theory.

makes democracy a seemingly futile solution to government

I am not sure what does "solution to government" mean, but there is a well-known Churchill quote: "Democracy is the worst form of government, except for all the others".

I am not into politics at all, but I think if you could change the following it would improve the political process. Currently politics seems to be based on arguing your position and gaining status for your team rather than seeking truth and the best policy.

• Politics is the Mind-Killer – Politics is not a good area for rational debate. It is often about status and power plays where arguments are soldiers rather than tools to get closer to the truth.
• Adversarial process - a form of truth-seeking or conflict resolution in which identifiable factions hold one-sided positions.
• Color politics - the words "Blues" and "Greens" are often used to refer to two opposing political factions. Politics commonly involves an adversarial process, where factions usually identify with political positions, and use arguments as soldiers to defend their side. The dichotomies presented by the opposing sides are often false dilemmas, which can be shown by presenting third options.
• Arguments as soldiers – is a problematic scenario where arguments are treated like war or battle. Arguments get treated as soldiers, weapons to be used to defend your side of the debate, and to attack the other side. They are no longer instruments of the truth.

A democracy is only as strong as the people that are people in it. It seems to me like politicians too often dwell on inconsequential, but politically important issues. They do this because voters care about these issues. The thing is, though, that voters are most often laymen. They are not experts. Therefore, I find it worrisome that politicians seem to discuss and change policies in order to placate voters. Obviously the opinions of voters should still matter, but when it comes to where politicians spend their effort and time. This should be based on what will provide the most benefit. I see two ways to overcome this: somehow get the voters more informed or change the political process somehow, this is related to the first point, so that there is less showboating, sycophantism and placation to the whims of voters.

• Privileging the question - questions that someone has unjustifiably brought to your attention in the same way that a privileged hypothesis unjustifiably gets brought to your attention. Examples are: should gay marriage be legal? Should Congress pass stricter gun control laws? Should immigration policy be tightened or relaxed? The problem with privileged questions is that you only have so much attention to spare. Attention paid to a question that has been privileged funges against attention you could be paying to better questions. Even worse, it may not feel from the inside like anything is wrong: you can apply all of the epistemic rationality in the world to answering a question like "should Congress pass stricter gun control laws?" and never once ask yourself where that question came from and whether there are better questions you could be answering instead.
• Error of crowds - is the idea that under some scoring rules, the average error becomes less than the error of the average, thus making the average belief tautologically worse than a belief of a random person. Compare this to the ideas of modesty argument and wisdom of the crowd. A related idea is that a popular belief is likely to be wrong because the less popular ones couldn't maintain support if they were worse than the popular one.
• Most peoples' beliefs aren’t worth considering - Sturgeon's Law says that as a general rule, 90% of everything is garbage. Even if it is the case that 90% of everything produced by any field is garbage that does not mean one can dismiss the 10% that is quality work. Instead, it is important engage with that 10%, and use that as the standard of quality.

Politicians need to become more aware of complexity and the feedback caused by their policies. Understanding system dynamics would help tremendously in this regard.

• Policy resistance - Frequently, a nonlinear feedback system will respond to a policy change in the desired manner for a short period of time, but then return to its pre-policy-change state. This occurs when the system's feedback structure works to defeat the policy change designed to improve it.
• Goodhart’s law - states that once a certain indicator of success is made a target of a social or economic policy, it will lose the information content that would qualify it to play such a role. People and institutions try to achieve their explicitly stated targets in the easiest way possible, often obeying the letter of the law. This is often done in way that the designers of the law did not anticipate or want. For example, the soviet factories which when given targets on the basis of numbers of nails produced many tiny useless nails and when given targets on basis of weight produced a few giant nails.

AFAIK domain experts almost all broadly agree.

The devil is in the details. They "broadly agree" on what? I don't think there's that much consensus on forecasts of future climate change.

As far as I can tell the experts don't agree

Who do you consider to be the experts and how do you know that they don't agree?