Memory/perception manipulation: There's a couple of tools, but likely the only thing you haven't seen is stuff traitors/secret maids can do regarding painting other characters as traitors, and secret maids seeming (badly) to be someone else. Ah, just in case, a major one is targeted forgetting of knowledge and characters to keep visitors from going hostile. If you have any ideas for what might be fun, let me know - the system might suit them.
Visitor hostile stage: It is a bit brutal; it's the 'things have gone wrong' stage and combat is meant to be messy (and possibly hard) early. It's a little tangential to your ideas, but a possible future feature during beta is an 'orange' stage, in which visitors are aware but not yet actively hostile/fighting (roughly, they know things are wrong and that the maids aren't on their side, but they're not sure if the maids are actively working against them/how dangerous it is/etc. so they'll do things you'd rather they don't but won't be openly fighting).
Combat: It's intentionally simple and messy yeah. Apart from the very late stage where you do the ritual (which you should be well prepared before attempting heh heh) it's mostly intended that it's avoided and that characters are handled in other ways (including e.g. letting visitors leave if they don't know much yet, or teleporting the manor to avoid cops/champions). Combat is things going wrong. I'm open to ideas though - I just want to keep the overall feel where it is (risky and ideally avoided).
Outfits: Have you seen the gardener/librarian/chef/nurse ones? More may be added, though it'll probably be a poll feature. Oh, and the alternate maid outfits option and just in case, the maid upgrade forms.