My two bits,
1. Some of the head gear quests are way too roundabout to or too grindy, so i suggest a review of headgear quests and their requirements.
2. Costume headgears should not have quests. They should be either from the costume shop, or from random boxes/drops.
3. Nerfing Bio 5, bio 5 content is pretty much impossible to solo, I understand that it was intentionally done that way to encourage party play, but I don't think that works here, specially when you can't tp around in the map, and the requirements for the headgear enchants/creation is so high. This kinda also applies to all instances which have drops which require large quantities for use.
Will edit this later with more stuff.