1. I'm a little confused on what your view of the "aff's job" is?
I'm in favor of allowing a debate over framework, but I ultimately think that there is a "correct" framework for debate. Here's more or less my belief:
1a) Debaters should have to defend the value of their model of debate against the alternative framework - that competitive debate with predictable parameters and policy focus is a worthwhile activity. That is, they have to win education and fairness style impacts in a traditional framework debate.
1b) If the negative's offense comes down to "you are excluding us from debate - our issues are important as well", I think that the "wrong forums" argument makes sense. I.e., that the presupposed basis of our discussion was a traditional engagement of the resolution. Disengagement of the resolution through a discussion of race in society might be worthwhile, but that doesn't mean excluding it from this forum is somehow uniquely racist, any more than excluding a discussion of the Syrian civil war from a medical conference implicitly supports Syrian genocide. On the aff, I think this sets up a strong permutation of the race K ("Race is important, we should discuss that - the fact that we haven't done so here is not a problem. All my framework standards - why debate is good - are offense for the permutation"), on the neg I think this sets up defense to the alternative aff's framework standards ("Discussing race and oppression are good, but other forums solve that better, which means they aren't unique offense for your framework interpretation" - in other words, a link take-out because those standards aren't intrinsic to policy debate).
2. I'm not sure that debate really reinforces entrenched interests of policymakers - debaters are required to think rationally about issues and critically examine them from multiple perspectives. Policy makers adopt bad policies primarily because they do not make policy based on rational examination of issues, but because they adopt one perspective when approaching an issue (Example: "Bob legislates in favor of unions not because union rights are good and he's weighed the advantages and disadvantages of this policy, but because unions give him cash and votes, so he has a personal incentive to give them benefits"). Debate divorces ideology from policy, which forces debaters to approach issues ground-up (notice the complete lack of debaters who are against open immigration - that's because there's basically no offensive literature against immigration).
Even so let's accept that debate pushes people to accept hegemony and imperialism as good, because this is the strategically "best" impact in debate (in terms of leveraging offense against the other side/turning their impacts) - so debaters are incentivized to advocate imperialism, and this serves policy makers' interests (american security thinktanks/military industrial complex). I don't think the activity of policy debate somehow uniquely contributes to an entrenchment of these positions, because these are publicly held beliefs anyway (in other words, the "serving the state DA" is non-unique). The only way debaters change is by a shift to the "left" (in either the anti-state/biopower libertarian left or towards an anti-cap left), which isn't the "entrenched interests" impact that the race K is talking about. In other words, policy debate controls uniqueness on this question, which means the only direction of offense is in anti-state education (everyone joins debate loving American imperialism because they're a microsm of American society, so there's only a chance that some of them will be convinced by the heg impact turns or cap K and turn out "good", so traditional debate has a net positive impact on critical education).
3. Speed issues - I don't find that this is actually a problem. Debate has a bad learning curve for novices in the first few weeks, and spreading makes the rounds unbearable for older debaters who haven't judged in a while or for spectators, but, ultimately, it's a net positive for the educational experience. Top level high school debaters very rarely lose rounds because they run out of time or drop arguments - the pressure of time limits+tons of arguments means they have to prioritize sections of debate, which forces them to think about arguments logically (in terms of identifying them syllogistically and picking out the weakest parts they can win on) and in-depth.
I'm upper-medium range speed, which means that I'm en par with most debaters but will have a hard time matching the top level of the college brackets in speed. But this means that I just have to get better in "big picture" debate (on the high school circuit, this is why I always went for long-term hegemonic decline impacts, because it allowed me to disregard some of the nuances of the disads, "homogenize" and group the offense, and win the impact debate through deeper analysis) - in other words, this lends itself to different styles of debate. Slower debaters will specialize in big impacts and kritiks (smaller schools also specialize in trickier strategies, because they can't overwhelm bigger programs with huge research resources through evidence quality), faster debaters will try establishing multiple points of offense (I'm a 2A, so our 1ACs on high school would have maybe two advantages, but they'd be long and well-developed: versus the 5 advantages that would "spread out" the other team).
Speed forces debaters to interact with a lot offense and get an in-depth discussion of a policy in 8 minutes. I ran a trade aff with a hegemony (and european war) impact, and instead of debating the predictable:
Trade good/bad
Imperialism good/bad
I had to debate these issues as well as biopower, the nuances of that trade agreement's passage and the strategy of the US trade representative, immigration, Mexican energy policy, cartels, the Asia Pivot, German automobile industries, Senate ratification process, Iranian nuclear proliferation, Brazilian relations, etc. etc.
Oftentimes, 6 or 7 of these in one round, and getting into the nuances of how they interact with on another. Bad teams might lose because they drop an argument and don't know what to do, but the top of the high school and college circuits, even if they are incredibly slow and drop an entire flow, will still be able to win because they'll be able to do better big picture analysis on the intersection of these arguments. Speed has a learning curve, but once debaters figure out how to overcome it, it doesn't make debate just a contest to see whose faster - it compresses more arguments into less time, which makes debaters think more critically.
I don't really see any problems with policy debate other than the conflict between debaters and those who kritik debate. Big teams (well-funded teams) obviously have strategic advantages, but these can be overcome through dedication (like Stef says, "the poor have advantages in society because they'll work harder than the rich - they'll find creative ways of displacing them"). I came from a smaller school, but I did a huge amount of research and probably matched or surpassed the total output of the best schools on the national high school circuit, and we regularly got into "upsets" and beat top-tier teams. So I don't think most of the problem arises from poor debaters just being helpless, but from those debaters disregarding the structure of the activity and using their poverty as a tool to "buy the ballot".
Otherwise, I think debate is a very productive activity. Some of the discussion on the high school circuit is a little shallow ("hegemony good/bad", for example - almost nobody understands IR, so these sound terrible when novices or even mid-level debaters debate), but that's just the nature of the game (13 or 14 year olds aren't going to sound like Mearsheimer or Nye - doesn't mean that the sort of immature discussions they're having aren't worthwhile, though). I do think that the policy "game" of debate disregards "first principles" philosophy, but:
1) That's not necessarily a bad thing - monopoly and Risk disregard philosophy too, but it doesn't mean it has to be included (again, race and kantian ethics don't have to be included in a forum just because they're worthwhile)
2) If people are interested, they can learn about these things on their own - debate would be a much smaller activity if this year's resolution were: "Resolved: Objectivist ethics are correct", because nobody would care, and the only people who would care/still participate in the activity are people who are already thinking about these things on their own (again, a reason why point 1 - the inclusion of these topics is not necessary - is true).