Casters having to wait a week to recover spells isn't like any edition of AD&D that I've experienced; 'sleep to get back your spells' is extremely traditional. If you want to use that to make adventures progress slower it's a standard variant rule, and will result in a slower game based around an adventuring week instead of an adventuring day, which may work for you. But it's not going to make anyone think "oh, casters needing a week of rest to recover spells, that harkens back to classic versions of the game!"
Largely agreed. Overnight-plus-study/pray-time is and pretty much always has been the default for spell recovery, and changing this - while perhaps a daring idea - will have some major knock-on effects once you start play.
The proficiencies with a really limited number of weapons is a weird gamey thing that has never made a lick of sense. The idea that a warrior who spends his time training to use weapons would be adept at using a footman's mace but clueless using a slightly smaller horseman's version of the same weapon, or that he'd be good at using a full size spear but befuddled by a javelin. I urge you not to have things include like this in your game: "Oh, I see you're able to use a long sword and a broad sword, but you're completely befuddled by the slightly smaller short sword and scimitar, or by a dagger. You'll need to spend months training to learn to use them" or "Oh, you're good at using this long pole with an axe blade on the end, however what you've found is a long pole with an axe blade on the end AND a spike on the opposite side of the axe blade, it will take months to learn how this weapon works".
The answer here is variable non-proficiency penalties. If you're trained in spear you might only be -1 when using a javelin or other similar weapon, but -2 when using something completely different e.g. a battleaxe. And a non-fighter trying to use an untrained weapon is even worse off - -3, -4 or even -5 depending on class and-or difference in weapon used v weapon trained.
I very much like the idea of individual weapon proficiencies, reflecting the in-game notion that a fighter - while vaguely handy with any weapon hence their lower non-prof penalty - has his-her own particular weapon preferences, and those are what he-she has chosen to focus on.
The opposite way to achieve much the same result is by a weapon specialization system that gives bonuses with particular weapons chosen by the player/PC, but that way lies numbers bloat and power creep. Penalties are better.
The idea that someone with a dagger will have an initiative advantage over someone with a sword is another hilariously unrealistic artifact from old D&D. If you want to see this in action, make a couple of mock weapons out of dowel rod, pipe insulation, and electrical tape, then get someone to go outside and spar with you. The guy wielding a sword-length weapon is going to have a much easier time scoring hits than the guy with a dagger-length weapon, he clearly has the initiative both in terms of striking first and controlling the fight. If neither person is exceptionally more skilled or athletic than the other, then the dagger guy is just going to lose over and over again. Again, I urge you not to preserve unrealistic oddities from old game systems for the sake of preserving them.
The point of small-weapon initiative bonus is not to reflect who will usually strike harder or inflict more damage, but to reflect who will usually strike faster. Assuming vaguely-equal levels of skill, the person with the dagger will be able to pull of a couple of moves during the time it takes the sword person to wind up and swing...particularly if the dagger person can get inside the swordsperson's guard.
Critical failures implemented as 'if you roll a 1, bad stuff happens' are also weird gamey things that aren't part of traditional D&D. They bias the game towards casters over melee unless you also include critical spell failures
Spell fumble possibility is IMO essential in any such system, as are aiming rolls for ranged spells.
and have the really weird effect that better melee combatants, who get multiple attacks, end up hurting themselves with their weapons much more often.
The chance of messing up, when pushing the edge of one's skill, doesn't change much as the skill improves.
As an example - I'm not much of a typist by any means but I'm almost certainly better at it than I was 20 years ago, at least in terms of typing faster. My number of mistakes per line typed, however, probably hasn't changed much if any over that timespan - I just make those mistakes more frequently in clock time because I'm typing faster than I used to.
Same can be true of melee fighters.
Lan-"the backspace key is always the most important button on any keyboard"-efan