@barnowl are you sure? i remember asking Kosmic to do some tests and from what i remember the slowest speed matched the slowest arcade speed and the fastest switch speed matched the fastest arcade speed (excluding the alternate fast speed on that home edition rom hack thing)

I mean I'd say yes I think it's allowed

I'd say yes. It's allowed for smb1 and it doesn't give you any advantage, you may get a slight time disadvantage because lower framerate, but it's basically like virtual console so I don't see why not, but I'm not a mod so to be 100% sure maybe you should wait for an answer from a mod

You can submit runs from any platform pretty much. The only thing banned so far is "alternate fast" in game speed

Yeah, I don't see any good reason why not, but the framerate is probably slightly slower and you'll lose a tiny bit of time. I think we should allow it until we see a problem with it

i've never tried openEmu, but on nestopia and fceu there's an "insert coin" hotkey you can set up. and if there's no insert coin on openEmu you can download a "VS super mario insert coin rom hack" on google, which is the same game but you don't need the insert coin feature on your emulator

Fceu or Nestopia are very good options for this game, I recommend setting up a key for "insert coin" in either of those so every time you reset you don't need to use the mouse to insert a coin before you can play. this is not like lost levels or any FDS games where you have to download a BIOS and set it up. as for the ROM you can probably just google it shouldn't be hard to find