It's somewhat at my discretion, but not really by intent. There are some rules about powering down and then burning 25% at a time as fast as possible, but when I wrote those I didn't realize that powering down requires adjusting the delegations first, and I wanted to coordinate that with the people running the anti-spam projects getting the delegations so it got complicated and somewhat delayed, but ultimately I'm still committed to never remove coins from the account except by burning (as well as it not being used to upvote, which would be a back door way to extract value from the account if allowed), which I feel satisfies the intent.
As far as commitments on the chain, they are there in the rules posts. Still, it's depending on trusting that i don't run off with it. If the amount got too large it would probably be a good idea to put it under a multisig with several respected community members having joint control. Eventually (far off) we might have actual on-chain smart contracts and be able to do it that way. For now, I think the current approach is okay.
Much appreciated. Got the full picture now. Thanks for taking the time to explain and address my inquiries in such detail.