Great idea. I think the first has been discussed Ad Naseum but second it very creative.

Pivx actually allows all users to gain interest though the rates might be higher for master nodes. I think stem dollar is inder utilized
Marketing the platform as steem bank where you have savings and a good interest rate (5 percent annual) paid daily would be huge. We really could be first decentralized bank. Dash will be there in a year or so and has better marketing so we need to move fast.

If we are going to have the complexity of steem dollars let's market it!