I didn't use a passkey to pair my MM - I selected the 'don't use a passkey' option.
As for BT management, sometimes I've had the icon in the system tray but it's not always visible so to pair the mouse I went thru the control panel to set up the pairing. Initially my macbook didn't see or recognise the mouse so I gave up. I tried it again shortly after and again it didn't show up in the list of devices but I got called away for about 10-15mins and when I got back the mouse had been recognised and then I managed to get it paired.
As has been mentioned about the right click - I've had the same problems sometimes it will take a good few clicks for it to work and there is a very slight delay (longer than a 'normal' mouse I reckon) for the menu to appear on screen.
I also noticed that my mouse doesn't appear to use Apple drivers.... In the device manager my mouse is just listed as a bluetooth HID mouse and all the drivers are provided by microsoft...