What specific statements were made by Ned or Steemit reps that are being characterized as a promise or contractual obligation to use the funds a particular way, and was an amount mentioned?

One very clear and specific statement from Ned, among many others mostly from Ned but also some from Dan, was that the ninjamined stake was all dedicated to developing the ecosystem. The statement was made in an interview widely viewed by cryptocurrency investors, so one can reasonably conclude that it was thus made in order to encourage such investors to invest. I know of at least one very large later investor who did carefully study these recorded interviews and statements in evaluating Steem before deciding to invest. That investor, along with everyone else, has every right to expect that the promises that were relied upon in making the investment will continue to be upheld.

Maybe Ned should have paid closer attention to Dan's warning that you quoted, but in fact he did not. (Though as an aside, one also ought to be extremely skeptical about "legal" theories coming from Dan, who later used similar theories to launch EOS, which was prosecuted and settled with the SEC.)

But, in truth, Ned knew perfectly well that his project and company would go nowhere unless he made these promises. People were not and are not going to sign up to put their own money (as well as time and effort) into giving something value where 80% of the money would then get sucked out by the founders dumping stake just to put money in the own pocket. So it was really the statements of Dan, not Ned, that were out of touch the the practical reality at the time, and with the actual practice.

There were many other statements that reinforced the model and intent, such as consideration at one point to transferring the stake to a non-profit foundation, a roadmap document that put forth a whole list of things the stake was going to be used to pay for (most of which, in fact, did not ever get done), etc., etc.

As a stakeholder, I support the decision of the witnesses to stop processing transactions and leave the stake in place until a better path forward can be worked out. Ned and Steemit used Steem and the ninja-mined stake as a manipulative game to mislead and deceive everyone else for their own enrichment for far too long. It was long past time for stakeholders to finally say, "No more!" Something like this should have been done long ago, and if it had been, less of the stakeholders' money would been unfairly and sneakily drained away. Still, better late than never.