Can I use the Emulator to run the MSX version?

Yes you can. The boards are just empty because so far no one has posted a run yet for that particular version

So even if my run is slow, much slower than others, it will still be approved?

sure enough, there is no problem if a run is not the fastest ever was or will be. feel free to post your run and good luck on your attempts! Remember to check the rules in case you need a specific setup for the openMSX emulator.

One of these centuries I will speedrun the MSX version, but I have been far too busy. I'd like to get the TAS done, which affects routing. Perhaps this can be the opportunity to discuss the routing, which will be vastly different. Both deathwarping and save and load are shortcuts. I initially routed this with deathwarping only, but now that I know about save and load I need to reroute.

I can help with the setup for MSX if you have any questions.