The one major problem with this idea is that it uses the steemit account's SP to dilute the curation power of people who have purchased and/or earned SP but who do not get elected as a super curator. That would be unfair and would also make it less attractive to accumulate steem.
In my view, it would be fine if, instead, it used the purchased and/or earned SP of other users who voluntarily make their SP available for others to do curation. Some people may in fact purchase steem knowing they can put it to use in this manner.
I guess that's basically the idea of delegated curation, which has been discussed in the past and may already be in the works. It would definitely be nice to have that as it would solve the same problem this post's proposal is trying to solve.
Yes that is true but I think the benefits outweigh the negative aspects in terms of dilution but that is a subjective matter I think.
Yes if we had that then it would be less necessary.
Edit: Indeed if we could get delegated voting working and combine that with a list of elected super curators who get at least a proportion of that then it could work very well. You would still get favouritism and people giving their power just to people that they know but the overall effect would still be better than the current situation.