Good issues to bring up. As you say, I was writing with the assumption of no significant disabilities. Given the variety of potential issues and disabilities, particularly issues amongst introverts, assuming that individuals would understand their own needs and take or adapt what they could was really the only way to write with clarity. As with the people who have commented about visual learning and hearing-impaired speech, these are things I couldn't cover in the post but are interesting to discuss in comments.

One thing regarding three -- surely that's the point at which one would talk to a teacher/manager about significant interfering issues, and arrange for an alternative or a proxy? I mean, a post on presentation advice, I'm not sure that even comes into it when someone is literally incapable of presenting.