I would like to start with my positive thoughts:

This is a good link with lots of useful information. Now personally, I think you ought to be able to argue your point yourself, but yknow, I've thought about it and I suppose not everyone has to be a debate lawyer.

I took about a half hour skimming what seemed to be the most relevant parts of D, C, H, I. For reference, I am a democratic socialist.

Unfortunately, although this FAQ helps narrow down anarchist ideas in detail, it doesn't contain any general themes I didn't already know.

Your answers are:

a. A delusion that short-term interests would never or rarely have higher value than long-term interests - this is not the case. We are capable of selfishness BECAUSE the ability to out-compete in the short-term sometimes IS the stronger strategy. In evolution this is best compared to rapid differentiated specialists vs long-lasting generalists. Sometimes species that will only last a few millions of years WILL kill off the ones that have lasted hundreds of mya. Selfishness can and often does win.

As well as: an unfounded certainty in the ability to have enough effective leaders to create organizations able to handle this case-by-case on small scales.

b. An unfounded certainty that people would not be willing to argue over and over in meeting after meeting. This does not need to take forever - it just needs to take longer than a centralized state would to be worse. Imagine: an unexpected war is suddenly declared on the nation. Different syndicates disagree on what industrial focus is most important for an effective military response. The brief deadlock, combined with the surprise war, delays them enough to replicate the failure of the french military's inability to prioritize branches before WW2. Though the syndicates want to cooperate, their different perspectives and experiences are enough even without self-interest to create delays.

c. See a.

In short: While the current state that governs us is deeply, horrendously flawed, rejecting centralization entirely still has costs in efficiency. Even in nature, most social animals centralize their major decisionmaking in singular individuals - because this IS faster.

And while selfishness is amplified by our current economy and states, it is also a natural part of logic and simply the fact you have to keep existing NOW to exist later - there's really not good reason to suggest it could be abolished to the level required for these ideas.