If you really want to learn about thread, I suggest you sign up for the monthly newsletter from Superior thread. They educate their consumers on all the topics you have mentioned, and you can send them any question and they will answer it. the beginning of the year they send out a newsletter with the top 10 questions from the prior year. They are usually the same questions, such as, the age old debate of poly vs. cotton, aging of thread, how is thread made, what does Egyptian cotton mean, what is long stable and extra long stable cotton and so on. you can subscribe by going to www.superiorthreads.com and going to newsletter. And BTW, their answers are educational in nature, not just telling you how their product is made or holds up or is better than the competition. It is well worth reading their emails.
Mindy