A) The Waiver Recommendations page can be used to help you take advantage of the waiver wire every week. The Lock and Limit functions also you to control what types of waiver recommendations The Machine suggests. 

Faq Waiver Recs

Using the Lock feature means that The Machine will only recommend add/drop transactions where both players are the same, such as a DST for a DST and a RB for an RB.

Using the Limit feature means The Machine won't increase the number of players of the selected positions. For example, if you limit DST, it won't recommend dropping an RB for a DST since this would increase the number of DST positions on your roster.

The % Win values are the values of the players on your roster if you lost them AND did not replace them. For example, if you only have one DST and you have five RBs, the one DST may have more win value than any of the RBs because you have backups for the RBs, but no back up for the DST. It is not trying to tell you in absolute terms that a defense is more valuable than a running back.

When running Waiver Recommendations, most users limit for K and DST positions and sometimes for the QB position.