Unconfirmed in 1.8 but I've added it to the list of releases (extracted from a chat with a moodler):
1) Editing teacher can hide his course. But with LEGACY roles can't see hidden couirses so he close himslef out of hi course. It shouldn't be available (the option to hide courses) unless they get the corresponding capability.
2) Editing teacher can view participants, select them for sending a message, then getting a mesage "you are not enabled to do this". They shouldn't see the option to send messages if they aren't able to do so unless they get the corresponding capability.