This is brilliant! Love it as a B/X fan who plays 5e.
Proofreading wise there are some examples in the ‘actual play’ section where Juan and Sarah are mixed up, just FYI. Also MM is given as just the one Missile for the wizard character. No biggie but thought May be useful to know.
In terms of names (always the biggest head scratcher!), here are some ideas for good or for ill:
(1) Be X (Very meta option, distilled rpg essence)
(2) Old Way (riff on Moldvay)
(3) 5 Easy
(4) Three Pillars (of game and of classes)