Like security, performance is a process, not an event. Each version of NetTalk makes it go faster, and contains a variety of optimizations. You're still using NetTalk 6, so you should assume that your site is less than optimal, from both a performance and security point of view.
Many of the items you listed below were addressed in NT7, others have been addressed in NT8. And there are many optimizations included in both of those, which are not included in your screen-shots at all.
Cheers
Bruce