1. When you send a private message to a bunch of people - the recipients cannot answer to all people who received the message because the system creates "unique" messages for every user. the recipient only sees the sender and not the other users.

it would be very practicable when a user would have the opportunity to reply to all people having received the message.

2. forwarding private messages would be very nice. Just an additional button "Forward message" instead of "answer" would work.