Did you/them get any response on these attempts? No response or an 'avoiding' response imply different things.

Our first experience was being told we could provide a list of questions for the AMA with Ned and Sun. After having carefully come together around aset of questions and handed them over, they were ignored in the AMA.

We continued to stress the urgency to know how if the new owner planned to use the stake similar to the conditions that have been made and taken for granted by the community and investors for years, namely that it shall not vote and be used to grow Steem, and were told that it would be a "high priority" to get that answered. It was asked more or less daily for the past 10 days.

What kind of measures should I think about? What would make you and your team feel confident we can let Justin Sun 'handle his stake' again? :-)

To me, there should be no possible way for the stake to be used for witness voting. Actions may include disabling the voting rights on the account (which can be done as an irreversible action by the account owner). It could also wait until a new hardfork where we limit the number of votes to 10 which would mean that nobody would be able to single-handedly vote in a sufficient number of witnesses to have a supermajority. I would also need a clear and public statement on what the intended use of the funds would be. At least it is something the community should know since so many have invested money in this chain on the assumption that this particular stake would be used to market and grow it. Whether or not I would fully agree with it is less important.

with some big ethical question marks I have not yet found an definitive answer on.

This was by no means an easy decision. But I believe it was the only responsible thing to do in the end. It feels wrong to deny network access to a certain user (which is what the witnesses are doing. No account details are changed. Nor is the blockchain changed. Access to it is denied), but I believe it would be irresponsible to allow an account to have the complete power to practically destroy everyone's value here. I don't want to assume bad intentions on Tron's side the way I've seen many do since the acquisition. Regardless of who the buyer was, such a vulnerability should not exist. Thus my main regret is not to see this action made, but that it should have been done 3-4 years ago in one way or another.