Thanks for this reply. As far as I know there were a few people who ran their own API nodes, but I'm not sure if that's still happening. There's really no incentive to doing that at the moment which is a problem.
Regarding verifying that different nodes are supplying the same data, I believe this is already possible since Hive Engine actually makes its own blocks that include the transactions in a single Hive block that are related to Hive Engine and their result. The Hive Engine blocks have a hash which includes the hash of the previous block, so you should be able to compare the hashes of the same block number between Hive Engine nodes to easily and quickly verify that they are the same. I'm not 100% certain about that, but pretty sure that's how it works.
Finally, about moving tokens between chains in a trustless manner, I agree that this is a "holy grail" and I know of projects like Cosmos that are implementing that across a number of chains that support custom smart contracts on the base layer. I don't know too much about the details of that, but I think it would be amazing for Hive if we could add something to the base layer that would allow the trustless transfer of HIVE to external chains. I would be open to supporting that type of project via the DHF or otherwise assuming it's feasible and there was someone who could actually build it.