The FATE system was a decent idea to implement but they never really committed to it enough to have it do more than be a source of easy exp.
They should be interacting with the maps way more than they do. Give us branching FATE chains depending on the FATE outcome. FATE chain success should be tied to levels of hostility in entire areas. Maybe opening up merchants with rare goods and collectibles. Maybe provide access to repeatable quests (maybe that reward bicolor gems) if an area is held long enough? Hell, make it so gathering nodes have bonuses while the area afinity is high. Something to inspire people to do them when they don't need the EXP anymore.
New types of FATEs would be appreciated too, preferably ones that aren't so combat focused. Events while traveling don't have to always be life and death.
Help a farmer literally whack some moles with a special hammer.
Help a noble outside a party arrive in the appropriate fashion by listening in on the party-goers.
(go -hide- and select certain points near clusters of npcs talking, dialoge box pops up with the conversation with keywords, go back to the npc and select the appropriate keywords. collect enough intel as a group and the noble enters the party with confidence and style)
Leap-of-faith/cliffhanger style jump-a-thons/collect-a-thons (instead of kill mob or pick up thing to get item) & deliver to npc.
Traveling carnival patrols the zone and sets up minigames on hotspots. Minigames drop tickets and you can trade them in while the troupe is parked. Once they complete a circuit the prize pool changes.
(And FATE NPCs should not disappear unless their character literally walks into an area in which the PC cannot go or see into. I can't believe I hate to say this about an RPG, because NPCs literally disappearing the instant they're no longer relevant takes me RIGHT out of the experience. Raktika did a good job with this on the huntresses chain, I want to see that continuity with every single FATE)
They also need to stop with the client-side NPCs. I get that it reduces server lode, but the Viis running across the road e-v-e-r-y t-i-m-e I enter the crystarium, or the dude who walks up to the nutsboard every time i walk into the area... they're getting old. If you're gonna do clientside events, make them small, and have a pool of what can happen and randomize it, because oh my god I feel like I'm trapped on one of those amusement park rides with the singing anamatronics. Zero immersion.
I'd also like to see more storytelling (environmental and mechanical) off the main path of a zone. I want rewards for exploring. Like the zones are somehow so linear in this game (il mheg is really bad about this in its design). Secret nooks with hidden quests. Multiple routes to get to areas. (shortcuts!) Areas that require puzzle solving or basic jumping to navigate. Just, things that inspire whims and reward you for following them. I play MMOs to recapture that sense of wonder and aventure I had as a kid exploring the woods. SE. Lemme chase an unassuming frog that no one would notice and get rewarded with a friend when I manage to catch it :3
They need to do some more reconnaissance on other mmos on the market on how they do their open worlds because i'm just so bored of XIV's lifeless backdrops for quests. (GW2 and WoW (again) specifically)