Search term in domain name should not have as much value as it currently does. Along similar lines, I think link anchor text is way overweighted as it's fairly easy to game for commercial searches and not at all common for the type of "editorial link" model pagerank assumed.

As it stands, link buying is rampant: as risky as black hat techniques are for real businesses, if you're building diverse spam web properties through a scalable model, it's not really risky at all. it's not like google can give you a permaban.