Since you mentioned Moe Norman, yes, I have played it for something like 14 years. My instruction was:
1: A Natural Golf VHS tape set
1a: A later NG DVD
2: a few lessons from one of their Certified Instructors
3: DVD's from Scott Hazledine: IMA Golf
4: DVD's from Graves Golf
I got a little something from all of it, although I'd say the NG stuff being first gave me most of what I ended up with.
In the beginning I used upright lies. Over time I changed to fairly standard lies. Moe actually was a flat lie player. The key is to align the club with your trail forearm. Most people hold it in the base of the fingers of the lead hand and in the palm but above the lifeline of the trail hand. That grip works in concert with the higher hands and arms. You can hold it in the fingers, and will look a bit more like Steve Stricker from down the line.
The swing is pretty is pretty simple, as you have found. Anyone who succeeds with it will have to match things up with their own body's timing, tilts, and other preferences. Fortunately for a guy like you, the adjustments will probably come for your own sense of what happens in a golf swing. So I am talking about more upright versus flatter, more tilt to the trail side versus less, more turn back versus less, more /quicker forward turn versus less/slower, overall tempo, etc. A wider stance will slow the lower body in favor of the upper, and narrower will do the opposite. I would say every year my swing evolved in some way. Lately I've changed to gripping in the fingers and less trail side tilt.
If you haven't already, look up Kirk Junge on Youtube. He has a ton of stuff on there. He started out in the original NG group of instructors. He has evolved over time, and I think he teaches two different flavors of it now.