Sorry but I haven't seen the video due to youtube being blocked to in China. The easter eggs I know are:
1. Song - using rocks
2. Tapes
3. Rocket that flys after playing all tapes, located in conference room after having pack a punched
4. Painting easter egg - found upstairs to the right of the lobby at the start
5. Radios in alley and theatre
6. Power boxes that you knife all already the map - no one knows what they do yet
Anything else like hidden papers and stuff like graffiti on walls I won't post about because I'm lazy.
Please no one ask about any of these easter eggs, if you search the names of the easter eggs I listed above, you'll get info on them
As for easter eggs on five, all I know as of now are glitches and stuff like that. I know about the music easter egg though.
Now, onto the rumour about the ladder at the back of the theatre dropping down. I'm not going to say that it works or not due to not trying it enough myself. But what some people say is that if you do all the easter eggs, Samamtha will drop the ladder for you to climb up. Some people deny this because they used No Clip to get up to the ladder, which turned out to be unclimbable.
Forgot one more thing on Kino. When the teleporter is linked, the light on the teleporter goes green. I read someone elses thread that said that there are other lights that light up if you do certain things and that there are 6 in total. No one has lighted up all six yet and so no one knows what happens when you teleport with all six lighted up. Some theories are that you teleport to a new room. Keyword there is THEORIES.
Again, I would like to say that I didn't watch the video so please don't flame me, just trying to help.