Most of us would agree on this idea This was floated around sometime last year as well. However, getting this through and making STEEMIT remove the vote on the return proposal would not be an easy task to achieve, unfortunately.

Who would run the account?

Not a single entity is what I believe should happen. Both this and the service to buy and burn STEEM should be set up by multiple trusted entities. A multi-sig account that requires the approval of all entities involved.