I really like your idea as it would further encourage honest interaction on steemit and split the rewards in a fair way. Someone who curates and interacts should definitely get more than someone who's just upvoting something.
We might still see that system being outsmarted somehow but it will definitely be harder to do than right now. I'm overall curious on the changes and improvements we may see on steem within the next months. Until then I keep upvoting as many good comments as possible :)
You'll find you get much higher curation payouts if you vote on comments, as a result of them generally not having (many) votes ahead of yours, and frequently being past the 30 minute timer.
I used to spend a great deal of time encouraging good commenting with large voting rewards...