Good morning to all. I intend to start running this game and i wanted to know which emulator (and its version) and game version (USA or EU) are allowed to be used. Thanks in advance.

"Any emulators are allowed, with exceptions of the ZSNES and Snes9x 1.4 and below."

I recommend the last version of Snes9x (1.60), Bishawk emulator with BSNES core or Retroarch with Snes9x/BSNES cores.

version of the game: both :)

regardless of whether it is an American or European version, both are accepted on the leaderboard. but I recommend the American version due to the fps gain compared to the European one (the European cartridges/roms run at 50fps against 60fps of the American version).

Game is now available on Switch (On the SNES Online App) so that version should be accounted too.

yes, it's counted as emulator too (since you are playing in a nintendo switch console) :)