The urge to tinker is awash. What TT might better mine and why?

As the owner of a much modified Lenco and four high quality DD turntables, and having owned a Notts Hyperspace before embarking on my odyssey with idler- and direct-drive, I feel confident in saying that any top notch vintage DD or any well developed Lenco or Garrard will certainly sound "different" from what you've got and in my opinion, better.  You keep asking "why", but most of the why is built into your own preferences, so it's hard to say why.  I can only say for myself that the idler and DD options produce music that is more like real.  You can read the cliches about rhythm and pitch elsewhere.

Uber, My only "Denon" experience is with the DP80, the best they made for home use.  Second only to the DP100 and DP308, which are both megabuck items these days.  I would shoot for a DP75 or DP80, if I were you.  The cost is only a few hundred bucks more than a DP3000, if that's what you've got your eye on, and the product is better developed (since it came on the market later than the DP3000).  (DP75 is essentially the same as DP80. I used to know the difference, but I've forgotten.)  I'd also suggest Victor TT81 or TT101 or Luxman, if you can be patient enough to find any of those.

Why is direct drive incompatible with an air bearing? Are you aware of a few of the vintage direct drive turntables that use magnetic levitation so that the vertical bearing is not doing much weight bearing.?