Cybergun is a rebrander. They don't make guns, but rather license guns with actual trades. So to answer your question about JP being Cybergun, the answer is no.
When I hear about a gun under the name Cybergun, I think a gun with trades. Not necessarily TM compatible, good, bad, or upgraded. JUST a gun with trades.
But depending on which CYbergun Famas you have, the answer is yes TM mags will work. The electric Famas takes TM mags, the spring Famas will not take TM mags.
Skip the formalities, it's Buster. The one, the only Buster
Newb (ignorant) = Inexperienced new player who's yet to gain correct knowledge.
Noob (stupid) = Experienced player who refuses to properly educate them self.
People tend to base risk analysis more on isolated stories than on data.