Steam used to have the Daisy Wheel input method (someone made a JavaScript(TM) port here: https://github.com/likethemammal/daisywheeljs), which I recall being very good in practise.
For Rad Type, I'm curious whether if basing it on Dvorak or Workman or something rather than QWERTY would improve it.
For issue #2 which is raised I would suggest using D-Pad Up for capitalisation and D-Pad Left and Right to switch between keyboards. The number row contains 13 keys with 2 characters each, so that's 26 characters just like the alphabet, which maps perfectly. The other special characters on a standard QWERTY keyboard are located on just 8 keys, for a total of 16 characters, which would work fine as a third keyboard.
For Rad Type, I'm curious whether if basing it on Dvorak or Workman or something rather than QWERTY would improve it.
For issue #2 which is raised I would suggest using D-Pad Up for capitalisation and D-Pad Left and Right to switch between keyboards. The number row contains 13 keys with 2 characters each, so that's 26 characters just like the alphabet, which maps perfectly. The other special characters on a standard QWERTY keyboard are located on just 8 keys, for a total of 16 characters, which would work fine as a third keyboard.