Lacee,
I agree with you totally about cables and wires and power conditioning. I have gone through quite a collection of wires and cables and power conditioners made by a dozen or so well-reputed companies. IMO, cables and wires and power conditioning are the life blood of a good system.
I have experimented with magnets for years. You need to find the kinds of magnets that work for you and the locations in the system that improve SQ. I have had some good results with this. But you can definitely overdo magnets. So you need to take one step at a time. It is all about experimenting and testing.
Regarding experimenting you stated, "It's harmless and you can always go back to normal with not loss of anything but your time and a few bucks." This is also my approach. I have done lots of experiments over the years. Most of what I have done cost me next to nothing. Occasionally, I have come up with a winner. So, the risk/reward ratio has definitely been in my favor through the years.
Regarding those "A rated products", they are usually replaced by A+ rated products within 12-24 months. And they are often driven by reviewers whose bias is not always in the best interests of the prospective buyer, if you get my drift.
You hit the nail on the head with the word "optimized". Most people end up with a plug-and-play mindset. But if one steps out of the box and gets a bit creative and adventurous the SQ that emerges may turn out to be head and shoulders above what it would otherwise have been.