with state chains you always have an operator that coordinates the swap of keys, and ensuring old ones are deleted, in spark setup as long as at least one operator is honest your good, they also cannot keep your funds you have unilateral exit. The downside of spark currently is bad privacy, and few operators all run by spark, so yeah for now you are trusting them to not collude with another party, but that's just how state chains work.

Yes! But what if the operator was a person or distributed set of people within a WOT like a federation. But all open sourced and easyish to run? Then spark the company wouldnt be needed. This is the idea.