I'd say there are two main problems for now in the game:
1. Locations feel dead
2. Unique Items and Builds
1. Locations feel dead
First, let's talk about the Wayfort: after rebuilding the Wayfort, there are several things one can do inside it. Random encounters, scenes with the NPCs, merchants selling unique stuff, and features unique to the location (vault and dungeon) make the Wayfort special and important, as it should be. Khor'minos, Kitsune Den, and Hawkethorne do have important merchants and scenes with the NPCs, but they lack the random encounters (Kitsune Den does have, if Kinu is freed) and any special features. Winter City and the Centaur and Marefolk Villages have barely anything. After one finishes the quests involving these place's NPCs, there is no reason to go back unless one wants to interact with Ahmri, Atani, or Hethia, for instance. The Kervus Warcamp suffers from the same problem (I had even forgot it existed before I checked the game again).
A mission to give these places a new, unique feature would be a great solution. I can see the colosseum as a unique feature of Kho'minos, for example. If one could enter the colosseum to face different challenges for different rewards (and maybe being sponsored by nobles and politicians like Arille), that would be a reason to keep returning to the city (instead of farming money outside of Lumia's fortress). In Hawkethorne, forming and training a guard and invest in the village's defences, and in the Winter City, help rebuild the city (and thus having more places to visit, buy things, and new scenes with Freja and Aileh, for instance), are examples of features I can think of now, other than the ideas that come from trying to solve problem 2.
To sum it up: add unique features, like the vault (Wayfort) and the Nursery (Hawkethorne) to the other locations.
2. Unique Items and Builds
There are actually three problems inside this topic:
2. a) Too many unique items that have lost utility thanks only to the fact that one adquires them early one. In other words, even if an item is perfect for one's build, it becomes obsolete solely due to it's low stats. One example is the Giant's Breastplate, that is outmatched by the Dragonscale.
2. b) Unique Items are far superior to normal items. This forces the player to make their builds around them, instead of completing their builds with the items.
2. c) Conflict between unique items
The problem a) is fairly simple, and it has horrible consequences to the development team. If unique items get obsolete, then the team needs to add new items. I'd argue that it is easier to allow players to, with a significant cost and challenge, upgrade their gear. the Captain's Greatsword is a perfect example of how that can be made (although I think the mission is too easy). Other solution would be making the stats of all gear scale with PC's stats (the team probably already thought of that, so maybe its not a good solution). If this problem is not solved, then the development team will have to add new, redundant items all the time and for every possible build a player can try.
Problem b) again is straightforward: unique items are regular items, but better. As a consequence, not only common items become obsolete after a certain point, but also the player is forced to use an unique item simply because of it's stats, even if it doesn't fit the PC's build or roleplaying. While I don't think making the unique items worse is a good idea, something has to be done. I personally recommend an upgrade/enchantment system in a manner similar to the weapon modification system of Fallout New Vegas. Make various NPCs able to modify the PC's gear in a manner similar to the alchemy system, like Viviane did with the dagger. Unique items are, as the name implies, unique, so if asked to modify/enchant it, the NPC will say that they're not confident in messing with the gear without destroying it, so they won't do anything besides improve it here and there (stat upgrade). With common items, though, they could not only upgrade it's current stats, but also add a new stat, perk, or enchantment. Something in the lines of add fire resistance in detriment of frost resistance or allows parrying, or even add fire damage to a weapon. These upgrades must be expensive, mainly in the endgame. They'd not only make it easier for players to have a build-specialised gear, but also make common items relevant again. As to how to improve unique items, I'd recommend the Upgrade NPC requiring both an specific item (ores, leather, cloths, and other resources that can be bought or, preferentially, acquired through battles in the world) and escalating sums of money (also, only one stats upgrade per PC level when it comes to unique items).
Problem c) is quite simple: some unique items are better versions of the others. For instance, Giant's Breastplate vs. Dragonscale, The Songstress Blade vs. Galon's Griefmaker, basically all belts and Helms, and Bessy Mauler vs. Beast Killer vs. Taeleeran Longbow. While there are differences between their stats, these items serve basically the same purpose. Other unique items have an special effect that make them, well, unique. I recommend doing the same for the rest of the items. The Beast Killer could deal additional damage against non-sentient animals, for instance, or the Giant's Breastplate could grant huge resistance to frost. This combined with the upgrade system would guarantee the relevance of all unique items.
To sum it up: add special effects to all unique items and add an upgrade/enchantment system to all (including regular) weapons and armour.
3. Conclusion
An upgrade/enchantment system would both partially solve problems 1 and 2. Want to upgrade or modify a sword or metal armour? Go to Vitruvius in Khor'minos. Want something enchanted? Visit Zuzaan in the Marefolk Village. My other suggestions require time to actually write the new NPC, missions, and encounters. Maybe having a dedicated month, like Mayternity, to it?
