"Did Jesus preaching commandment really extend to all christians?"
This is an interesting question. JW's have what I term the "Clergy-Laity Distinction Doctrine". And, of course, we all know that they proclaim that there is NO SUCH DIFFERENCE!!!!
There are scriptures that indicate that "some were given as this & some were given as that...". These scriptures don't indicate the JW hierarchy or support it.
"Are there other religious orgs who attempt to decipher current and future events to be linked with the prophecies in Revelations? (or in other words are JWs the only ones who claim to know who the UN and other nations represent?)"
There seem to be a fair number who have taken up the chrono-prophet role. If JW's have dropped off that one, others have risen in their place.
In the "olden days" Armstrong (WWCOG) used to do lots of this. I have seen Jack van Impe wax heavily in the Chrono camp. I have noticed others on the I-Net, but didn't note their names.
Perhaps there is some "law of conservation" that applies to Chrono-Dubs and their brethren. Some of them are TV-evangelists, so the entertainment factor has been enhanced :)
Best wishes on your encounters.
Mustang