First of all, thanks for contributing!
Please consider filing separate tickets for separate issues. Having many different comments stuck on a single issue makes it extremely difficult to discuss them separately. This doesn't count for obviously wrong things like markup, grammar or spelling errors.
Screenshots demonstrating issues are extremely helpful and highly encouraged.
When mentioning page numbers, please use the page numbers that are noted on the page itself. This can be different from the page that a PDF reader thinks you're on due to cover pages.
Feel free to submit pull requests, although all of the above counts as well.
Use gender-neutral pronouns where appropriate. For example, when talking about an attacker, use "they", "them", et cetera instead of "he" and "him" or "she" and "her".
When talking about specific people, use the gender pronoun they prefer. Also use gendered pronouns when using placeholder names like Alice, Bob, Carol. Mallory could be of either gender, but she's a girl in Crypto 101.