It sounds like you would make everyone into a merit source with an unlimited amount of smerits and I don't think that would work. On top of that, anything based on ranks is doomed to fail. Ranks don't make the person or their judgement any more valuable.
That's without even going into the pitfalls of negative merits/downvoting. This has been discussed a lot, particularly at the start of the merit system, and I don't recall any particularly robust abuse-proof ideas on how to implement it.
Well only one of your upvotes on one post would be worth about 0.01mrt, so you'd have to upvote one user 100 times in order to give him one merit, therefore much more people would have to agree with the post being good or helpful or whatever, therefore that post would get at least merit partially since there's a chance like this that it wouldn't get merited. We all know what's the definition of merit, and a lot of people finding a post useful or helpful or informative is enough to be at least acknowledged.
btw I did acknowledge that there are a lot of high ranking users from the time before merit system.