I think it is a good idea to go over the items, it is fine to get the exiting sets complete. But that said and that it i I think we are drowning in items.
I think you need to either be more modest with that - and maybe less greedy to be honest- I know you need to earn money on this game - but it has turned into a nugget circus. I have no prove of how it would be with or without this - but I know that you are loosing players on this, as well as cashing in.
With all those item - you do need to do something about the inventory. Splitting the product section into 3 would be a good start. Products, buffs and recipes. And do you really want to add those strange fair buffs- I don't think many of us like them - they have very title use - and just take up room.
About the friends bar- do remember that most of us like list to be vertical - and that it is nice to be able to use the scroll function of the mouse.
I hope you have not forgotten the chat. I still hope to get a more reading friendly version again some day soon. Most players are used to it now - but it is till hard for many of us to read. Using colours is also hard on a dark back ground.
Duel change first step is okay. If friends bar make optional (what want use: old or new at settings) more people like this.
Multiplayer Instances: after some test I can write about feedback. Sounds like all good, but what decide I can shoot bear or not? Luck, skill points or maybe arcade game and need good reflex?
New quests idea I like but every time need x npc KO is not fun. Some game (like Forge of Empires) at quests have got alternative choice. Conquer or buy these lands.
the travelling fair balancing to make construction more lucrative.