unfortunately i don't think there's a way to adapt minecraft to a tabletop role-playing format if we think of tabletop role-playing games as vehicles for collaborative story telling, or role-playing as pretending to be a character. however, in my recent blog post (link), i discuss how what sets old-school dungeons & dragons from other games is how it is an open and infinite system. you need both of these aspects to encompass the creative play of minecraft: there should be few strict rules (let language do the heavy lifting), and there should be no absolute goal in sight. there shouldn’t be a realistic narrative  either, since we’re talking about minecraft where days are twenty minutes long and players can dig massive tunnel systems in that amount of time.
i think the best comparison is to how most board games don’t ask you to distinguish between you as player and you as character. when i play minecraft with my friends, i don’t make that distinction. i’m the one punching the trees, sowing the seeds, etc. this isn’t to say anything stupid (as a lacanian) that there isn’t a split between player and “character”; obviously you’re only punching trees in the game world, and not in real life. it’s the conceit that your character has a personality that i think wouldn’t mesh well with minecraft.
so keeping this in mind, i think this frees up a lot of possibilities to make something geared towards creative play. the rest of this post is just me coming up with random ideas for how this might all work. these are not all consistent or complete, but i hope it sounds fun! feel free to tell me any thoughts you have :)