After two weeks, I had to bail on not having anything on the top row and put numbers back on the top row.
I also brought parens and brackets back to the base layer. It was just too hard to do vim sequences like 22d. It turned it into [layer change] 22 [layer change] d. Things like `array` also involved two layer changes.
I'm still avoiding reaching to the sides, though; we'll see what reaching away does to me.
In good keyboard customization news, having one key for copy/paste/cut (tap, double tap, hold) is working well, as well as double tapping U and H for the parens.