While you get a warning when changing servers that your characters are not shared across servers, there is no warning at all that your crown purchases can't be shared across servers either. Any DLC, houses, assistants, mundus stones, etc that you bought with crowns are available only on the server you bought them.
Stuff you buy with real money - ESO Plus, Morrowind, Summerset etc - that's really account wide.
Favourite NPC: Wine-For-All
Mostly PC-EU , with a lonely little guy on NA.