I would make use of Kevin Crawford's Ashes Without Number settlement rules. The base game including these rules is free on DriveThruRPG, and like the rest of his work it really is excellent, especially for worldbuilding and exploration-based play.
How long does the rest last in this paradigm? And are you taking it because that's the minimum allowed time between rests, or because you happen to be in a place where the rest is possible?
None of those games are going out of their way to present an unintentional system that can appeal to the broadest possible customer base. They all have goals beyond just getting everyone to buy their game. I've seen no convincing evidence that WotC has such goals, and I refuse to believe that...
Again, do you think a complete redesign of D&D is likely to increase WotC's profits over where they are now, without any significant drop in the meanwhile? That's IMO what would need to happen for WotC to do as you suggest, and they'd have to be pretty darn sure it would break that way.
Would all that testing result in a game that would make WotC even more money, enough to compensate for the time lost to development? Becsuse if not there's no way they would do it. And they would have to be pretty sure it would increase profits, because they've been shown to be pretty...
I guess. Never understood why a company like WotC can't just make a successful game that people like and pay for. It has to be number one, with all the annoying knock-on effects associated with that need.
Not sure what you intend the end if that sentence to be. I know D&D has more players. I also know all those games have players and are successful by their own standards.
There are modernized/updated versions of B/X with more options, like OSE and ACKS II. And there are more modern games inspired by old school ideas like the Without Number series and Shadowdark. It doesn't have to be the official game.
The Rules Cyclopedia was pretty great. My favorite version of a D&D-like game is essentially an iteration on it and it's close cousins. That being said, 5e is a great base for a D&D-like game too, and easier to find players for, so it's an excellent alternative.
I had a mentor when I learned on BECMI, and later on 1e. Neither system had a combat balancing system that rated monsters like CR does. Hit Dice is different.