do it here, or on a sub reddit as a stop gap
its fine! in fact better than that, eg nxt did a complete code review and launch that is over a thousand pages long, doge as well handled a massive view rate easily, there there is the goldcolapsing up thread, some million/200K views or something
or put up a google docs excel or something to aggregate issues if you so chose.
This will be far more robust than probably any other forum, and the migrate later.
make up a emunieproplems@gmail if needs be.
even a twitter feed for bugs could work
All of your recommendations are 'maybe' viable options, but only IF they had been the communication medium from the beginning. However, switching to them now would invite further confusion among the base of existing users, not to mention the utter chaos and confusion this would present to those with whom we are truly trying to attract: the average joe (ie. the less than 1% of the world not already part of us crypto-nuts.)
In addition, without a forum where we can express the ideology in a clear and structured manner there would be limited methods at our disposal to ensure no misinformation was presented to the user. This confusion among new users would only serve to limit wider adoption. Moreover (and not to denigrate this forum and it's goals), but to have an emunie thread within "bitcoin"-talk would then imply that we are effectively no different from all of the exsting and newly created "bitcoin"-like solutions. This is absolutely not the message we want to portray. Same implication with pretty much every other proposed solution (although I do appreciate your providing them as reference).
In the end, the medium of communication is not primarily about being "robust" (although this is important and is being addressed), but more importantly an ideology of having the utmost respect towards the one truly deflationary currency ALL of us have in limited supply: Time.
Basically, there are many of us that don't have the 12+ hours a day that are often needed to scan, search, hope and pray we can find the "true" answer to our question on a product we decide to spend our 'time currency' on as would be the case with the proposed alternatives. In addition, once you go down the path of using these alternative mediums it becomes infinitely more difficult with each passing day to migrate back to a more polished and structured environment.
Not sure about Doge, but even the Nxt 1400+ page thread has recently commented on how challenging it is for them to imagine a way to transition from their "1" hyper-long 1400+ page thread and instead "try to move the conversation back to the structured forum they already have" for Q&A. Challenging indeed. Even more challenging for a 'new' user thinking about using Nxt.
Its much like the restaurant example. You go out to eat one evening and your considering 2 new restaurants that are side by side with each other. One has a huge amount of people already eating (1400+ pages and growing at the rate of 2+ pages per hour) and one where no one seems to be at all (structured forum). Which one do you choose? Oh sure, if you had an infinite amount of time (ie. not really hungry) to research each then you "might" choose the less popular one, but the majority will go "where the action is at".