It would be really cool to have a PageRank-link algorithm that answers the key questions:
However, Ciro has decided to leave this for phase two action plan, because it is impossible to tune such an algorithm if you have no users or test data.
Perhaps it is also worth looking into ExpertRank, they appear to do some kind of "expert in this area", but with clustering (unlike us, where the clustering would be more explicit).
Other dump of things worth looking into: