One other thing for which the OP's friends might want to have English answers ready: "Are you on the Dining Plan?" (This will be asked by cashiers and restaurant servers whenever they are ordering food and beverages). Also, teaching them to recognize the words and symbols for "Standby" ride entrances and "Fastpass"/"FP+" entrances (and even phrases like, "is this the end of the line?") will help them avoid any confusion about which line to enter or where to wait, as the queue entrances are often right next to one another, and during time of heavy crowds, temporary queues are often set up which can extend back beyond the marked entrance (usually with a cast member at the very back, holding up a tall sign that says something like, "End of Line').
Other than that, it just comes down to common courtesy -- some non-language related tips would be: obey directions from cast members (Disney employees) and ask for clarification if you don't know what they're telling you to do, avoid engaging in loud or distracting behavior while on attractions or at shows, don't litter, at counter service restaurants clean up the table and take care of trays/trash when you've finished eating, etc. Also, I believe the tipping customs here are similar to Brazil: we usually tip anyone who handles our luggage for us ($1-$2/bag), servers at table service restaurants (~20%, unless the gratuity is already included in the price, as with the Hoop-Dee-Doo Revue dinner show - if it's included, that information will be clearly indicated when you make your restaurant reservation), hotel housekeeping ($1-$2 per person in the room, per day), and cab drivers/rideshare drivers (15-20%, unless the gratuity has already been included in the price).
I believe the My Disney Experience app (which has maps, wait times and other tools, and can be used to organize and modify dining reservations and Fastpasses) can be used in a number of different languages, and might also be a handy tool for gathering information, finding nearby restrooms or dining venues, etc.
