When you buy steem the only logical place to store them is in Steem Power.  Else you are subject to raging inflation. It's very hard to come to a solution to a system already in place but here is a few possibles roads.  

- I would not touch any kind of redistribution at all.  Doing this will scare all investors away we don't want that.  If it must be done then linear distribution from the 85+% that was self given to the owners at the beginning in a linear fashion to every account is the only way i see plausible. Basically everyone has been losing because of how the system started it's only fair to reroll the dice fairly for everyone.
- Curation should be back to 50%+ make investors beg to buy this thing.
- The free SP we get everyday should be given only if you are considered active.   Basically if you did invest, curate, post comments, post articles in the last week you get your SP for the following week.  

- If you invested in the last week you get a bonus of some sort more temporary curation power etc.. .  
Inactive accounts would get obviously much less SP or no SP at all. Since more than 90% accounts are doing nothing giving their reward to active users would explode what they get everyday. Even minnow would be getting something out of this ( usually we can expect 90% SP per year if only 10% stay actives they get 10x more SP ).

This would be and amazing incentive to participate. Basically thoses who make this place great to visit would get tons of benefits passive dead account would not.

This would encourage people to log in and do something, investors would be rushing to buy in and would probably slow down powering down. Curation is probably the key to investors they have to make a return of some sort at some point, else it's not investing anymore it's donating and that won't be very popular.