It all sounds great to me. Just a small suggestion: individual users should be able to 'disable' their own view of 'dislikes' on their posts. There are two reasons for this. Some people are simply unable to tolerate 'anonymous' 'dislikes' or 'disagrees.'
They just flip out and go away. Secondly, sometimes one member harasses another by clicking on 'disagree' for everything that person posts for months.
On another website I am on, the choice to turn off your own view of the disagrees on your own posts has, I hear, saved many a member's sanity.
Note that other members can see the disagrees on your post, even if you can't.
If you are dealing with something involving skills, management or techniques (the other website - crafting - and this one -managing diabetes), a significant number of disagrees can be useful info.
It can be useful, or manipulative.
There are a few on here, in my observation, where they have a real reaction to anything certain others write. In other words, if X writes the grass is green, Y would feel compelled to disagree, stating the grass is in fact another colour. Using dislikes (or likes for that matter), as a metric to valuing a member could be extremely flawed. As you may have observed, some posters use the like button, it seems, to acknowledge every post they read, irrespective of their feelings about it. On that basis, a poster could make 100 benign, newsy or game based posts, but get 500 likes. With respect, promoting such a person to a higher status on that basis may not be best value (in terms of diabetes management, which is at the heart of the forum, surely). Similarly, that someone is a "good egg" doesn't mean they are knowledgeable or,credible in their advice.
The idea of "dislike", I am ambivalent about, but if we are to have positive affirmations, it makes sense we could get some value to a not in agreement status. Whilst others might think this would bring additional discord, I could counter argue, it could be more benign (in terms of poster reaction) that the disagreeing poster appearing (to the original poster) to be calling them (the original poster n idiot, or ill-informed.