Power downs: if one is more of a curator than content creator then powering down would not be the best idea, in my opinion, but on the side of constant content creators powering down is a way of cashing out the max out of rewards.

Witnesses: I have only 5 votes I guess, but I can recommend at any time @dragosroua as a witness that cares for the platform.

Regarding your idea of delegating SP I see it as perfect. I wouldn't choose bid bots either, but I wouldn't like seeing it rusting for days.