1) A complete rework of this game's desastrous Inventory System, splitting Weapons and Tools and Gear based on Job Types up and increase the total amount of inventory space. Give players base 3 Retainers instead of 2. 1 per Gathering Job.
2) A complete rework of the Materia System, they shouldn't provide Stats, all Materia Stat Points should be part of the Gear Stats, Materia in FF14 should work like in FF7 and provide Skills, Abilities and passive effects in combat as support to help individualizing our characters.
3) Improval of the Photo Mode, there are definetely better Photo Modes in other games to get inspired by, Horizon Zero Dawn for example has a pretty good one.
4) Final Character Progression, by giving all Jobs with Levl 90 or later 100 true Master Jobs
- Warrior > Berserker
- Paladin > Crusader
- Dark Knight > Templar
- Gunbreaker > Guardian
- Bard > Minstrel
- Machinist > Technomancer
- Dancer > Gypsy
- Ninja > Shinobi
- Black Mage > Elementalist
- Red Mage > Spellblade
- Summoner > Runologist
- Samurai > Shogun
- Dragoon > Dragoneer
- Monk > Champion
- White Mage > Cleric
- Scholar > Sage
- Astrologist > Chronomancer
5) Minigames for Gold Saucer > Blitzball, Snowboarding, Motorcycle Hunt, Submarines and like in FF7 a Battle Arena with Handicaps where other players can bet on or against you ^^
6) Hunting Grounds, where Combat feels more like Monster Hunter World with for all jobs designed skill sets for these instanced maps that exist just for engame raiding/farming, FF14 definetely needs more endgame content, other then only 8er/24er raids, dungeons n trials. Eureka had this kind of vibe for that, but skill sets n overall combat gameplay was left untouched