Humans-Only Holmes Basic D&D

Taking another quick look at the Holmes Basic rulebook for D&D, I'm thinking about two different ways I would want to run this version of the game. One would be to use it as a lead-in to an OD&D game, with the Holmes + OD&D Ref Sheet by Zenopus as a bridge between the "blue book" and the "little brown books" if necessary. I've been wanting to run a sort of pseudo-"Arnesonian" campaign in the style of Delta's "Outdoor Spoliation" games, The First Fantasy Campaign, and Adventures in Fantasy. OD&D seems like the natural fit, but the little brown books can be hard to parse and unfriendly to newbies, so it might be more fruitful to keep them as DM-only material at the beginning of the campaign and use Holmes Basic as the initial player-facing rulebook. Correct me if I'm wrong, but from my understanding, Holmes Basic is essentially just a (partial) reorganization and clarification of OD&D material, albeit with a few idiosyncrasies (e.g. five-point alignment, cheap scrolls, to-hit rolls for magic missiles) and TSR-mandated references to AD&D. The OD&D Discussion Forum even includes Holmes in their banner picture of OD&D covers at the top of the page. It could be useful to treat Holmes Basic as a sort of OD&D starter set.*

But my second possible approach is what I want to discuss for now. I could also see myself running Holmes Basic as a more-or-less self-contained system using an expansion like the Holmes Reference Sheets by Zenopus or Meepo's Holmes Companion (a link to which can be found HERE). I think this would be an especially fun way to run a megadungeon. But the more I think about Holmes Basic in this context, the more I think that removing demi-humans from the game is the way to go.

What do dwarves, elves, and halflings add to the game, mechanically?

• Better saving throws for some characters? Fighting men really get the short end of the stick in Holmes compared to demi-humans. I'd rather ditch the demi-humans and have human fighters save as dwarves and halflings, rather than as thieves.
• Infravision? Honestly, I'm not a big fan. I prefer to either have everyone need light to see, making the management of light-producing resources more important, or else have the dungeon lit well enough for everyone to see and ignore that aspect of the game altogether. When some PCs can see in the dark and some can't, I feel like it would be too easy to wind up in a situation where lighting matters just enough to be annoying and time/thought consuming, but not enough to lead to any interesting or fun situations.
• Detecting secret doors and "slanting passages, traps, shifting walls and new construction"? That's what the thief ought to be for! Just let thieves do those things at the same dice probability that they use to "hear noise".
• Wielding the +3 Magic War Hammer? Do we really need one specific magic weapon with race restrictions? Fighters are all-purpose weapons masters; just let them use the dang hammer. Heck, thieves "can use all the weapons of a fighting man", so let them use the hammer, too.
• Beginning play with more spoken languages? If you don't want language barriers to be a big factor in gameplay, this doesn't particularly matter. If you do want language to be a big deal, I feel like you kind of run into the same problem as with infravision above: languages become another minor detail to track with little benefit in doing so. Having a dwarf and an elf in your party eliminates the need to worry about miscommunication with dwarves, elves, gnomes, kobolds, goblins, orcs, hobgoblins, and gnolls. On top of that, you've got alignment languages, the "read language" and "esp" spells, certain magic items, bonus languages for every point of intelligence above 10, and a 20% chance of monsters speaking "common". Do you really even need to worry about languages at this point? Getting rid of characters who automatically know a bunch of free bonus languages might help make miscommunication become a real problem if that's what you want.
• Fighter/Magic-User hybrid characters? With so few default character types, I think niche protection becomes more important. Even with their slow advancement, I feel like elves have a real possibility of upstaging both fighting men and magic-users. If you make some of the changes suggested above - give dwarf saving throws to fighters, let thieves detect secret doors and special architectural features like elves and dwarves do, and eliminate infravision - then I could be persuaded to keep the elf as a fifth "class" and only remove the dwarf and halfling. But honestly, if I'm dropping the other two demi-humans, I'd rather drop elves, too.
• Immunity to ghoul paralysis? This only applies in very specific situations, so I wouldn't worry too much about it. Besides, ghouls are scarier if no one gets to shrug off their special ability, right? Still, if you really like the idea of allowing the very specific scenario in which most of the party gets paralyzed by ghouls and have to rely on the only unaffected (type of) character to save them, couldn't you just give this immunity to clerics? It makes sense for their holy nature to protect them from these undead creatures, if you ask me.
• "[Vanishing] into woods or undergrowth"? Again, that seems like the kind of thing a thief should be able to do.
• A +1 to hit with missile weapons? Characters who need weapons and armor "cut down" to their size? Honestly, I don't think these are interesting or vital enough to worry about.

I think that in a simple, pared-down version of D&D, it's enough to have four character types with very specific individual roles and abilities. I imagine it also helps if the thief is a bit more vital to the exploration process, and the fighter feels like the toughest character. I don't have a problem with players being demi-humans simply as a matter of flavor if they really want to, but I'd prefer not to attach mechanical advantages to one's choice of race at the expense of the four "core" classes or the choice to play a human - that is, in this very stripped-down, "starter set" kind of experience I'm imagining.

Don't get me wrong: it's not that I think demi-humans are somehow "un-Holmsian." When I read Tales of Peril by Dr. Holmes, I actually really enjoyed the way all of the fantasy races co-mingled, not only on adventures, but in everyday life as well. I'm not against that flavor of fantasy - sometimes I find it incredibly charming. I love the idea of casually hanging out with a centaur and a pixie at the tavern. The proliferation of playable races in Wizards of the Coast-era D&D doesn't really bother me.

It's just that I think the way non-human characters are implemented mechanically in D&D can leave a lot to be desired, and from a rules-based perspective, I think a capital-B Basic game of pure low-to-mid level dungeon crawling would benefit from a greater focus on the "core four," especially if my rulebook of choice is going to be the lovely blue volume I've grown so fond of.

House Rules Summary: Remove the dwarf, elf, and halfling as PC types. Fighting men make saving throws as if they were dwarves or halflings. Thieves can detect secret doors and special dungeon features as if they were dwarves or elves (and their ability to do so advances as per their ability to hear noises). Thieves can vanish into undergrowth like halflings. Fighting men and thieves may wield the +3 Magic War Hammer. Clerics are immune to ghoul paralysis like elves.
EDIT: And give thieves d6 hit dice, for goodness' sake!

*Does anyone remember the "Dungeon & Dragons Adventure Game" starter set from 2000? Not counting video games, I believe that was my entry point into D&D. I got it for Christmas the same December I saw Fellowship of the Ring in the theater. It was magical.