In a Boeing 777 there are circuit breakers for the cockpit voice recorder & the flight data recorder however they do not stop them from working. Once the breaker is tripped they switch to their internal battery supplies. Both boxes contain batteries to power themselves since they each have sonar beacons used to locate the boxes in an underwater crash.
Far 25 25.1459 states that "Any single electrical failure external to the recorder does not disable both the cockpit voice recorder and the flight data recorder." So disabling the bus on these box wouldn't have been enough.
None of the electronics went off before their last communication. Where is your source for that? There were alot of blogs that assumed that since the last Acars signal was at 1:07 am and the last communication, "Good night Malaysian three seven zero", was at 1:19am it was turned off. However that means nothing since Acars works in 30 min increments so it's next message wouldn't have been till 1:37 am. The system could have failed anytime between 1:19am and 1:37am.
Cell phones would not have been able to work at that distance and speed.
The flight's satellite phones wont work if eletronics are off.
The US used custom Black Hawk helicopters that were designed for radar evasion. Not only that, helicopters are about 1/10 the size of a 777 and hover a few hundred feet above the ground using terrain to hide their signature.
"Also, some governments like Pakistan may be involved in the disappearance."
Have you looked at a map of southeast Asia? Do you know how many countries would also have to be involved in order to get the plane from Malaysia to Pakistan? The plane doesn't have the necessary fuel reserves to fly the known flight path, then deep into the Andaman sea, then to arc around India but be hundreds of miles away to avoid radar, and then cut through the Arabian sea into Pakistan. The only way for the plane to make it to Pakistan is for it to cut through the airspace of several countries including India. Why would all of those countries, especially India, all couloute together and do that?
No, that pun based joke goes back to 1936 at least.
1936 November 3, Oregonian, New Bid Called Sut-Over-Suit by Sam Gordon: The Kibitzer, Page 8, Column 5, Portland, Oregon.
"And remember: Evil will always prevail, because Good is dumb." -- Spaceballs