Are you willing to shorten the SP power-down period to three to seven days from current period?

Yes, but 7 days is too short 6 - 4 weeks sounds more reasonable.

Are you willing to remove down-voting policy of STEEM blockchain?

To be negotiated and planned. Other witnesses suggestions are interesting but there might be other aspects to be thought of.

Are you willing to introduce smart contact into the STEEM blockchain?

Yes, I'm supporting this idea as I believe it will add value to the chain by giving more opportunities to developers.

Are you willing to introduce a paid subscription model?

Yes, if you are thinking allowing the chain to become a kind of decentralised Patreon. Content could be stored on the chain but access is restricted. Developing this on-chain instead of in dApp is an initial investment that can save time and money from projects owners who can then focus their effort on their product rather than the technical aspect of implementing the subscription model.