I've noticed that point #4 influences what units the Rebels get, especially for (Re)emergences or Loyalist revolts (i've never paid attention to the other types of revolts). I don't know what effect, if any, they have on how many units the Rebs get. But they do seem to get whatever upgrades you've got in your province when they appear.

Thus, it's a really bad idea to build Armorsmiths or Master buildings in Khazar before 1230.... there's no need to make the Horde better than it already is