If you open up the Sidebar (use View-> Sidebar or Ctrl+B) and select the player model you've added, one of the boxes will be labeled equipment. You can select a set of equipment from there (the sets themselves are defined in public/(your mode)/stats/generated/equipment.txt). You can edit appearance like face and hair under the VisualSet box.
Note that the default equipment layouts (i.e. Class_Rogue) don't have armor. I'm not sure, but I also don't think npcs will equip stuff that they don't meet the requirements for.
If you want them to be hostile, change the Alignment box to "Evil NPC". You can add them to your party by checking the IsPlayer box, though I don't know how well that works. I suspect at the very least they will dissapear on map transitions unless you check IsGlobal as well. I don't know how Henchman and Companion hiring works yet, but it probably takes a bit of scripting to make them hireable.
