1st (and 2nd) point states that "almost everything depends on programmers". We must trust them! .. And what if they went rogue - someone threaten them (mafia, governmet, ...) or they lose their head - they can introduce all kind of problems - 1.1 exploits 1.2 different exe than given open source ...
I am not clicking in your video as well. I will just answer here .
If the developers Juat go "rogue", there will be a fork and nobody will accept their rogue code.
3rd states that there were cases in which big pools had >50% compute power .. I do not think that we have any protection against that right now? Or not?
There are more than 30 pools mining blocks every day and each of them do not hold more than 20% hash power.
Even if they decide to join forces, a 51% attack would not be profitable for them as btc price would collapse and they would at most revert one transaction and be kicked away from the network forever.