Updated to 4.0.2. Problem persists...

Can anyone help me with this? I am not pro Linux, have been loosing my days with this *** and can't get it working.
I got Version 4.0.0 build-53 2016/04/19.

Greetings everybody,

I am building an retro style arcade machine for one of my friends using a Rasberry Pi 3 with a Recalbox on 32 Gb sandisk class 10 micro sd card. I go the last release 4.0.1 running.

I configured everything, WI-FI, scrapper, SNES and NES USB Controllers at my place and tested the games and everything is working fine.
I bought arcade controller set with 2 joysticks and 2 DragonRIse USB Decoder one for each player. (http://www.ebay.com.au/itm/251628881305).
Installed everything, Recalbox detects it and I configured it in the main Recalbox Menu Settings - Controller and could see both of them. I maked sure the buttons order connecting at the encoder is exactly the same in both of them.
#0 Dragonrise INC. ...ick
#1 Dragonrise INC. ...ick
When got in a FBA Libetro game all the controls get mess up and I was even missing keys couldn't even exit the game. So, following some tutorials around I connected SNES Controller as a 2nd player and one of the DragonRise Usb decoders as 1st. Retroarch Menu -> Changed Player 1 Inputs Keys and saved config (using the SNES and Keyboard to help with it), that player was well set and saved.

My problem now is how to do exactly the same procedure for the second player with the Arcade DragonRise USB! Because in the retroarch FBA Libetro there is no Start or Select or Hotkey to open the RetroArch again to config the 2nd player. so When I move the SNES or Keyboard from player 2 to USB input player 3/4, I cannot get in the retroarch anymore.

Moreover, I never achieved to have in the retroarch both DragonRise Decoder showing at the same time. I think there might be a conflict as they have exaclty the same name.

Couldnt find any tutorial showing how to config both. I have some IT background but I do hate Linux ahaha Do someone have an idea how to solve this?