I skipped October and November owing to election season, but opening back up:
Top-level comments should introduce arguments; responses should be responses to those arguments.
Upvote and downvote based on whether or not you find an argument convincing in the context in which it was raised. This means if it's a good argument against the argument it is responding to, not whether or not there's a good/obvious counterargument to it; if you have a good counterargument, raise it. If it's a convincing argument, and the counterargument is also convincing, upvote both. If both arguments are unconvincing, downvote both.
A single argument per comment would be ideal; as MixedNuts points out here, it's otherwise hard to distinguish between one good and one bad argument, which makes the upvoting/downvoting difficult to evaluate.
In general try to avoid color politics; try to discuss political issues, rather than political parties, wherever possible.
As Multiheaded added, "Personal is Political" stuff like gender relations, etc also may belong here.
Depends on the relationship. In some relationships, the sub gives out a set of limits, and other than that the dom has free reign. In more extreme ones, there's even a master-slave relationship, where the master definitely has power over the slave.
I skipped October and November owing to election season, but opening back up:
As Multiheaded added, "Personal is Political" stuff like gender relations, etc also may belong here.