How To Make An RPG?

Hello! I was thinking about making a ttrpg based around Dragon Riding, because I love such a concept but most of the ones that do exist are for rules-lite systems like FATE or PBTA, so I figured why not. But I will be frank: I have little in the way of ideas of what I am doing. So what advice for how to do this would people suggest? What mechanics or concepts would people suggest I add? Here's a few things I have in mind so far.

MECHANICS

  • I want this to be a good mid-range rpg, more mechanically complex than something like PBTA or FATE but not as crunchy as PF1E or GURPS for example.
  • I am thinking this will be a skill-based rpg, so instead of the players having different classes that give them their skills and abilities, players "spend" experience like a currency to improve their characters. There will also be something akin to a Talent or Merit system that gives characters unique traits or abilities, like being better at directing their dragon during flight or knowledge of different kinds of alchemy to use for crafting.
  • Dragons come in one of several basic "Types" which provide them their starting attributes and a single free "Trait," specific physiological abilities a dragon has like fire breath, camouflage, enhanced vision, insulating feathers, etc. To reflect the enormity of individual species - for indeed I think this setting would have A LOT - players choose two extra traits when making their dragon, and they cannot be changed after chargen. For example, the Firedrake type is your archetypal dragon, a basic four-legged two-winged all-rounder that starts with the fire breath trait.
  • Additionally, I am thinking that I take a page from Predation's book: Every player controls both their character and another player's dragon, at least in roleplay.
  • I think I want to have a solid, robust equipment system. Maybe take notes from how Star Wars FFG or the Fallout RPG do it? Not sure. Maybe it'll even include printable cards that players can use to keep track of their gear's traits.
  • I think I will have it where different armor protects against different damage types. So for example plate is REALLY good against Piercing and Slashing damage, but it has trouble dealing with Bashing damage.
  • Instead of the setting having a magic system, it has an Alchemy system that ties in to the crafting rules: Making a magic sword is different from waving your arms around and chanting in gobbledygook, you have to alchemically enhance the metal that the sword will be forged out of.
  • Dragons and their riders have a pool of "Bond" points, representing the bond between them. These Bond points can be spent to do things like boost rolls, power through superficial damage, and refresh abilities like Fire Breath.
  • Maybe a D6 based game? Every point in a skill or attribute adds d6es to a pool?

LORE AND SETTING

  • While I think it is very common for this world to have fantasy air support riding atop the backs of flying beasts (Griffons, Drakes, Pegasi, etc), riding dragons is a bit rarer. Its not supremely uncommon but it does mark your characters as a bit exceptional.
  • While magic DOES exist in this world, it is not something humans are capable of wielding like your traditional fantasy wizards. Rather, it seeps into matter - organic or inorganic - and can be refined and harnessed via alchemy.
  • As a consequence of the above, dragons and monsters and whatnot are flesh-and-blood creatures, so you will not find monsters like the Volcanic Dragon from MTG where its an animated inorganic substance taking a draconic shape.