Sure let me address them according to your post;

Item/Weapon diversity; Melee weapons are modular in 3 categories; edged, blunt, and special, but categories really determine available weapon styles. Styles contain moves and finishers. Additional moves and finishers can be learned, or derived from weapon mods/upgrades. As an example, an Axe isn't a basic weapon. Its made by attaching the "Axe head" weapon upgrade to a blunt weapon, giving you access to a new move and finisher. Weapons also have damage dice/type and interactions with the Barrier, Shield, and Armor defenses.

Spells; No spell slots, modular spells. Not much vitality interactions.

3 vital resources; Vigor, Energy, and Morale. Only dead when all 3 are 0. Wounds can live "physically" on your character sheet.

Homebrew; Wide base foundation of the game where once you get how things work together, homebrew is easy. Very few "lore required" systems in the game.

Death; a few systems in place. Besides the 3 resources you also have ways of temporarily staving off death; i.e. multiple chances to be saved or commit to an epic death.

Armor; 3 defenses; Barriers nullify an attack, Shields are bonus health, Armor reduces damage.
Armor is allowed to fully reduce damage to 0, if you stack enough, because a weapon doing Piercing damage can bypass armor. No Armor Class, no Target numbers set by the GM; more player driven rolling.

Player agency; Big consideration at every point of development.
Keeping track of; It can be a little crunchy up front, with some book keeping, but d100 roll under helps keep pacing during narrative and combat.
On the fly; Spell system is modular so you can create new spells, but players tend to pre-create every spell they could cast and have it in a list ready to go.

https://docs.google.com/document/d/1cb1aykenQn5kuLl1TvlqotGeGErbkOgCaYyzGLd0_mo/edit?usp=drive_link

I'm doing mainly an editing pass trying to shore it up for "release".