Im going to opt to just ignore the stuff I no longer care to talk about.
I'm am sincerely curious(and not to rip it apart) to see what sort of optional rule system for potions instead of resting you can come up with
Posts 71 and 75 cover my idea. In short (or rather, long form as it turned out), resources are consolidated into one of two universal resources, which are the things that get restored by potions.
Abilities, spells, etc all have a cost of some amount of these universal resources, and some might have their own internal resource as an alternative (ie, daily powers).
This in turn would be coupled with a robust crafting and gathering system that would be the primary source of potions, but would also support all the other fun things players might want to craft.
I don't know if my idea for crafting is original to me or not (as I haven't quite found anything like it thus far), but the idea is something I called 7Dice. You roll 7 standard RPG dice and from this you get 6 different values. Each rolled value corresponds to some component or step in a crafting process, and the values determine the final properties of the item. These values can then be modified using skill and energy based modifiers (instead of attribute mods I consolidated them into the 3 energies, being Composure, Mana, and Stamina), and can benefit from certain class features, which allow you to customize them. Once you set up the item in this way, the final crafting budget is added up and it determines the DC you roll against to confirm the item, and degrees of success determine what you finally get; failing doesn't mean you get nothing, but succeeding really well does come with benefits, giving incentive to level up the relevant skills and, by extension, other skills to get your modifiers up.
Gathering meanwhile hooks primarily into a better codified travel activity system, which means even if a player doesn't want to go on direct quests to seek out components, they can still benefit passively as they and their party go off to do other things. Gathering corresponds to different skills, and the idea is that miniature skill challenges (with varied constructions based on 7Dice, see below) would be used to resolve the specific travel activity.
So say you're wanting to gather some metal to Smith with. You'd take the Prospecting travel activity, and the resultant skill challenge for Mining would determine what you get; using 7Dice as a basis, you'd have a specific set of dice you'd roll starting with a 2d10 skill check, which is what gives you your base prospecting chance to find some mineable ores. From there, you work your way down, rolling 1d8, 1d6, and 1d4. Each step represents the process of ore extraction, and spending your modifiers to get better rolls gets exponentially more expensive as you move down the line. The basic strategy, in essence, is to try not to spend your modifiers at all until you confirm your 1d4, which if you had at least some moderate successful values on your other rolls, means you can spend to get as much ore as you can. But, if you can roll high across the board and spread your mod equally across all the dice, then you can better ores and more of them simultaneously; the benefits of rolling high but also being very skilled.
Overall the idea behind 7Dice is that its meant to be quick to adjudicate even at the table. Much of the think-work can happen simultaneously with other goings on at the table, and for both gathering and crafting the idea is that you'd have planned ahead of time what you were going for, which would also speed things up. Potions meanwhile, as well as virtually everything else you could think to craft, would all follow this same core mechanic, making it relatively easy for players to swap between different crafting and gathering types, with the variety and interest coming from the different effects different components add to the items.
I haven't actually sat down and hammered out how Im specifically going to do potions (Im only just getting into my mages, and they're the ones that will have more of the relevant class features), but theres enough meat there to make some very interesting options for players to mess with, and as always there will be plentiful alternatives. Potions will be lootable and buyable, but these ones will mostly only be comparable to the ones a player could make at 0 Herbalism skill; player crafted items would more or less always be better, but the game wouldn't need them to function at a basic level. (Though it would be difficult to still be relying on them by level 30; at that point you could afford to employ an alchemist, so theres little reason not to eventually have the good stuff, even if you don't want to bother with doing the crafting yourself)
But anyway, this system overall results in a more functional system for a variety of reasons. First and foremost is that it hands resource management entirely over to the players. There is no arguing over when to get powers back. You either have the potions or you don't, and its on the player to be adequately prepared.
This in turn makes the GMs life easier, as you can design according to what they're prepped for, or can just design fixed encounters, and they either come prepares or they don't. No need to go out of ones way to balance the game, because it already will be by virtue of how the new resource system works.
Which, is the next big thing this would do. As player resources are no longer tied to adventure design, balance can be achieved per encounter.
More still has to be done on the intra-party balance when it comes to 5e, and for that matter in monster design, but insofar as resource management goes, these systems would provide simplification
and more depth simultaneously and where it ought to be. GMs do not need to have complex considerations just to make the game functional, and players by and large tend to appreciate robust mechanics that are flexible enough to be engaged with by choice.
Hooking gathering into travel activities also helps to make the process of travelling into something that actually has a point to work through rather than skipping it outright, and I don't think we need to argue over whether or not exploration needs help, and when combined with, by my experience much more fun and interactive travel mechanics (based on the Tension pool), you get a lot of mileage.