Need some advice/information. I will be installing unifi tomorrow!

1. Anything I need to know before the installer comes? I mean aside from the information on the front page of the thread.
2. Will there be any drilling if it is a hi-rise? From my understanding they will just need to open the door to communication room and do stuff. Is this correct?
3. Do I terminate streamyx now/ASAP or do I tell the installer about termination tomorrow?
4. Is it possible to keep my old landline number?

Thank you all