I currently hold around 17,200 SP, this gives me the ability to upvote content and give the author 0.20 USD.
Prove it!
Haha, but seriously, the problem is not SP, it's Steem, that's the real point of failure and the answer to the question of "where does the money comes from?"
Many here voiced our concerns for weeks and months but Steemit is not really a platform where criticism and dissent is highly valued. No smart trader or long term investor will keep Steem price up forever, it inflates no matter what you do (powering it up just make it dilute its value slower...).
The only possible solution I could think of is to monetize the site via ads and make companies "pay" by buying Steem to support daily/monthly payouts and Steem price.
RE: Adding special features for Dolphins and Whales.