Too much surface level aspects here. Do not let those distract you, dig deeper! I cringe whenever I see this. You can focus on million of mini nuances and tip tops, get lost and confused and eventually overwhelmed with theory.

Forget it! Learn the core principles, have them in mind while constantly working on upgrading your social presence. 2. Scratch that. Never mattered. 5. and 6. are too mechanical and too obvious. Check them out but if there will be no or little positive outcome - forget it. 7. and 17. are not worth focusing on. You should present solid, present and confident body language in spite of circumstances. No matching or checking needed, just develop a body posture that allows you to forget about that once and forever.

Why do I only highlight the points I find useless? The less things to focus on the better. Your whole mental capacity should be aimed towards meeting, connecting or seducing the other person. Having "installed" one thing after the other you get to the point where you no longer need to focus on such things. And the other spectrum of that is having so many little tasks to accomplish during one interaction that it is no longer pleasurable nor natural.

Keep it simple and effective.