Great graph and chart! Admittedly the numbers were somewhat arbitrary (I merely took the original ratio between commenting and activity rewards, and did a +/- 0.2 with the original author reward). For me, the key is the point of the post, not any particular set formula. If some of the more important people ends up seeing this post, I'm sure there will be a great discussion about just exactly how to tweak the formula. It'll be much better than anything I can come up with.
In terms of what metrics to use for how "established" a poster is, I think Average votes per post could be important. I'm not sure if there should be a cut-off (i.e posts over a certain amount of time, say 2 months would not count) or not. Again, if we can spread this message and get some important people on board, we'll be able to have a great discussion on the specifics, and come up with something better than any single person would think of.
I think vote weight is more important than average vote per post. Obscurity on Steem comes from not having enough whales voting on your post.