Thanks for your feedback ! 

I wouldn't add too much work to let all three slots be changeable so that's fine. 

In the next hard fork we'll likely have : 
- Chain id change (to truly set us appart from the steem chain) 
- Delayed voting (to avoid having exchanges powering up everything at once and then voting like they did before) 
- Some fixes on apis here and there 
- Changes on the sps to make it go from steem.dao to another account (@hive.fund)

On the complexity, the whole point of the way RC delegations are implemented where other people can set their slots, is to make it in order to offload the complexity to power users (aka the account creator / top witnesses)