I haven't so much as looked at BYOND in a very long time, but I recall it being a simplified, almost Python-like language to learn. Assuming you can handle learning the language, you'll be fine. Just backpedal a bit and make about ten simple games first, just to learn different aspects of the language. More important than learning the language, though, it learning to program. Yeah, they're different things. Learning bad style or technique can kill you later.
I remember DM being pretty simplified. That's great for learning, but it also somewhat limits you. I know DM is capable of what you want to do, but you might have to jump through a few hoops to do it. Honestly, I don't remember. It's just a rule of thumb that with simplicity comes limitations.
Good luck on the game and ask if you need help. The BYOND Developer forums are probably useful, and if not, there's always here. Your idea sounds cool, but, and not to discourage you, ideas don't do much until you figure out how to implement them. Many projects die young because the dev doesn't have the motivation to make it happen. Just keep your chin up and power through it. Write as many mini-projects as you can while learning how to do it.
And do yourself a favor...it doesn't matter what it is or how unpleasant the process is...once you start a project, finish it. Just finish it. Don't abandon it for any reason other than "I need to learn how to do this first". And even then, learn that one thing and go back to the original project. Never have more than two projects at a time; one main and a second where you learn things you need for the main. You ideally shouldn't have a second very often.