Okay, I might be able to help with a few of these but you might need to give us more information about your setup.
It might also help to read through the documentation if you haven't already.
1. TWO SETS OF CONTROLS
We need more information about how you have your controllers wired. You might not have the player 2 wired correctly. Pictures are also nice.
2. FIRE BUTTON
This is also dependent on which emulator you are using and each game will use different configurations for what they what you to press for the "Fire Button". You can override controls per emulator/system and per game.
Can you use two sets of controllers at the same time (player one and player two)?
You can use 2 sets and even 2 completely different controllers at the same time in 2 play games.
Is there something to enable to use two sets of controls?
I believe all the RetroArch emulators don't need any extra settings to enable 2 player support.
Can you designate one set of controls as player 1 (with Start, Select, Esc etc) and have the other set as player controls only?
I think so but I'm not sure what you're asking.
Or is there a kinder way to shutdown? I can only see restart from Emulation Station.
Make sure to gracefully shutdown your Raspberry Pi with the Shutdown or Restart menu options in Emulation Station. If you switch off at the wall before the Raspberry Pi has completely shutdown, that can cause file corruption. It would be like booting your computer into Windows 10 and just pulling the plug from the wall. That could also cause file corruption.
4. TEXT FILE SETUP
Yes you can put custom button mapping and monitor settings in a file. See 3 for monitor.
For controllers it depends on the emulator you are using:
Here are the Custom RetroArch Override Examples
For example, if you wanted to override the button mapping for the SNES. You would put those in
Now If you have a couple games that have wonky controls, you can add a specific custom button mapping just for that game. Look at this doc under "ROM-specific settings":
An example I use is for Metroid on the NES. To switch to rockets in the game you have to press the Select button but my Hotkey is also the Select button which can cause some undesirable results. So I made a new file named
Metroid (USA).zip.cfg and put it in the same place as my ROM which is named
Metroid (USA).zip and is located in
~/RetroPie/roms/nes/. I'm using an Xbox 360 controller so I wanted to substitute my Xbox/Guide button to use as the new Hotkey. This is what I put in my
Metroid (USA).zip.cfg file:
# Hotkey button input_enable_hotkey_btn = 10 #Guide