For my money, the best challenge to Dennett’s position on how to understand the role of introspective accounts in psychology is Alvin Goldman’s ‘Science, Publicity and Consciousness’ and the most stimulating work being done from a position relatively consonant with Dennett’s is that being produced by Eric Schwitzgebel. If you’re interested in introspection you should check out his new book ‘Perplexities of Consciousness’ but at the very least you should have a look at some of the papers he has on his website on the subject, especially ‘Introspection, what?’ which has what I believe to be the only published ‘boxological diagram joke’. Dennett has responded to a number of criticisms in an article entitled ‘Heterophenomenology Reconsidered’ though you may need a journal subscription to access it, I don’t remember if he has made it available on his site.
As regards the qualia point, obviously (?) there have been papers and papers and papers offering definition after definition of qualia, however one taxonomy which I’ve found useful with regards to clarifying the discussion of the connection between qualia and attitudes towards consciousness is Hugh Frankish’s ‘Quining Diet Qualia’ which distinguishes ‘Classic’ ‘Diet’ and ‘Zero’ qualia (after types of Coke) with ‘Zero’ being the kind associated with Dennett (as well as the type Frankish is inclined to defend) and Diet being associated with materialists who nonetheless have a robust account of qualitative consciousness and the introspectibility of the same (such as Michael Tye, Ned Block and Peter Carruthers) - this would be the sort of ‘materialist qualia’ implicated in the notion of qualia inversion or qualitative absence (zombies), both of which Dennett claims are intuitively tempting but incoherent notions. Frankish’ taxonomy is useful for linking the issue of qualia back to introspection and clarifying in your own mind how what might seem like separate strands of Dennett’s thought tie together and contrast with other leading contemporary philosophers of mind.
I agree that emphasis on critical thinking and analytical skills should be an essential element of any programme but from my admittedly limited experience the IB approach does not go as far in this direction as one might desire. Caveats; 1) the IB ToK element is better than the nothing most curricula I am familiar with have and shows the good intentions of those setting up the course, so this is not a ‘it’s no good’ but a ‘could do better’ comment and 2) not having gone to a school which taught IB, my experience has been limited to the handful of students I have discussed this programme with or offered ad hoc tutoring to in connection to the ToK element.
From what I can see, though the actual process of what is taught in classrooms and how it is taught may differ, in terms of what students seem to be producing at the end of the course the ToK element amounts to little more than Epistemology 101 where rather than being, as you put it, about ‘how to think, not what to think’ it is instead about ‘what to think’, just at a meta- level; ‘what to think about thinking’. If you wish to stimulate critical thinking I’m inclined to think intensive classroom based discussion of comparative analysis of arguments and source handling is superior to teaching the difference between the a priori and the a posteriori, or raising the possibility of absolute scepticism. I say this with no prejudice against epistemology, as a philosophy postgraduate student some of my best friends are epistemologists, but if the question is ‘what would be the best way to structure a curriculum so as to raise a generation of genuinely critical thinkers’ I don’t believe the answer is teaching them about Plato’s myth of the cave or the disputes between empiricism and rationalism. Perhaps such basic distinctions require some coverage, if only to avoid obvious howlers such as failing to recognise the use/mention distinction or the like, but for real critical thought it would seem better if the curriculum was structured so as to emphasise critical thought in all subjects in the form of subject-specific problem based critical analysis.