1. theyre out on the balcony i think but be sure to get fucked by the master in the master bedroom first (maid outfit) so the mistress can fuck you and put you back inside, as long as you dont get in the bath you'll remain with his scent on you so she'll always punish you and put you inside
2. i still havent put a room there even though the games almost done.
3. there's no definite point because the things you can do can be done in any order (except for needing the maid outfit for the chef questline)