You can check out pet info on:
pets guideCilencio Cerbera made a Pet leveling thread
Pet levelingI made a Pet 101 thread:
Pet 101I gift you an immortality potion when you hatch your first egg.
Ashton has sold diamond currency/items for Windlyn currency or trades & they have a item shop.
As far as item registry I don't think a complete one has ever been done but there are event item lists.
Plus, check ALL the shops for items you can purchase.