CmdShiftToCmdE.json

{
  "title": "Languages",
  "rules": [
    {
      "description": "Command + Shift to Command + e",
      "manipulators": [
        {
          "type": "basic",
          "from": {
            "key_code": "left_shift",
            "modifiers": {
              "mandatory": [
                "left_command"
              ]
            }
          },
          "to": [
            {
              "key_code": "e",
              "modifiers": [
                "left_command"
              ]
            }
          ]
        }
      ]
    }
  ]
}

@lirdis yeah, I also noted that there is still some stuff which doesn't work or work a bit strange with this configuration:

• "Shift+Command+R" in Firefox to reload a page with cache flushed: only works if I press and hold "Command" than "Shift", than "R" but not "Shift" than "Command". Which is a bit clumsy (I'm not used to) but works.
• Shift+Command+V to paste without formatting doesn't seem to work. "first Shift, than Command than V" just gives V and "Command than Shift than V" pastes with formatting. But here, to be honest, it's a Mac-specific thing, I'm not sure if it always worked for me even before.

I haven't yet bothered to troubleshoot this (not enough tedious as a problem :) If I ever find a solution, I'll let know here.

Please also do if somebody else knows how to fix this.

Ah, and also Shift+Command+4 or +5 for screnshots/screencasts. But here I just redefined them to Control+Command+4/5.