Can the client and server be installed on the same machine?
yes you can install them both on the same machine.
I even managed to install server and client on android.
As kammed says, absolutely they can.
The key thing however is that the CMS library and the Player library cannot be shared. You must configure them to be different locations on disk.
That means that if you upload a 100MB file, it will occupy 200MB of storage while the layout containing it is in the schedule - since the Player will download its own copy of the video file to play from.