I don't know about allowing all servers to shut off premium items.
It would be kind of bad that if all servers decided to turn off premium items and all of a sudden something you paid for is no longer usable
Well, seeing that at least the Kickstarter bagpack is nowhere near "overpowered", I guess only those with a really good reason ("hardcore last man standing"-servers e.g.) or jerks would do this.
Well and not so many jerks are going to spent money on a public server only to ruin it's reputation
You can store items wherever you want in the world. We just can't guarantee the world won't frequently reset during Alpha. Most people will want to restart worlds to get the new content we add (and keep the world from breaking entirely.) So keep really important stuff in your (decently sized) inventory, and play on a server that you trust.
Well Alpha is one thing.
Talking about the actual release and ultimately the choice we will end up with (per-world or persistent) is what I had in mind.
Let's see where this is going, but nevertheless l'm going to curse you guys anyway, since no matter how big my bagpack is going to be it won't be enough.
One hell of an ingame collector : "Keep everything you find and that is NOT 100% proven to be useless, since it could be of use somewhere,sometime!"