I have a couple suggestions for Istaria, ordered from what I think would be the easiest to Implement to the more difficult ones.
1. Building Banners
Banners with the symbols on them matching the crafting trainer plaques in towns
(To identify craft buildings from a distance)
Banners with different resource symbols (Brick, Bar, Cornucopia symbol, Spool, Orb, etc.)
(To identify resource types in silos from a distance)
2. Storage Mannequins
Mannequins that open up a mimic of the Equipment screen to store 1 complete set of gear
(1 type for Dragon, 1 type for bipeds)
3. Treasure Chests
Small storage item to be placed inside of buildings
(would need extra coding to have it show on top of building's floor instead of just on the ground)
4. Property Details Page enhancements
a. Flag: "Hide Scaffolding"
Makes everything on the plot look as it would after final build similar to the Planning Page
(So even after some things have been placed and partially built, owner can plan farther)
b. Tab: "Resources"
Has a list of all the resources needed on the plot. Can place resources here instead of each building
(Placed resources would be apportioned according to the order of the buildings on Construction tab.
5. Building Enhancement Quests (Select building then use enhancement item)
Vertically generic buildings such as library, silos, warehouses, guildhouses, etc. can be enlarged vertically
a. Stack Enhancement (not available on silos)
Increases base stack by 50%
b. Capacity Enhancement
Increases base capacity by 50%
c. Defense Enhancement (Walls, Towers, Pillars, Gates, etc)
Increase wall height by 50%
6. Guard Outpost T1-T6 (Lv. 10, 20, 40, 60, 80, 100)
Looks like guard outposts near each settlement. Requires item similar to the one needed for Consigners
There is one type for each biped class type.
Once built, double click on outpost and it opens an "Equipment" screen to equip guard with gear.
Guard will combat creatures that wander into the area
Healing classes will heal players upon ask (might be a "purchasable" heal)
Buffing classes will cast buffs upon ask (might be a "purchasable" buff)
More Ideas forthcoming as I think of them.