The first and seconed post are up to date. The patch is for people who have versions 1.1.0 or 1.1.1 and want to update to 1.1.2. If you download 1.1.2 directly you don't need to patch. Basically the whole WolfRevolution mod is 385MB, the patch is 6MB, so udating is simpler with the patch, but you can do a full install if you want, also if you have an older version of WolfRevolution, 1.0.X, ie anything before 1.1.0 you'll need to do a full install of 1.1.2, the patch wol't have the necessary art files.
In terms of the add ons, they are optional. The Wolfshanze purifier removes super spies and my changes, and the Revolutions purifier makes all Revolutions default Revolution mod component values. I really don't recomend the Revolutions purifier, but some people will probably like the default way of things better (early game it's much harder, it's impossible to stop any city outside of 5 tiles from your capitol from rebelling). The Wolfshanze purifier will be overwritten by inquisitions if you install that add on though, likewise if you install the Inquisitions add on then the Wolfshanze purifier, it'll overwrite super spies and inquisition files, basically removing them.