Recently I meet a monk, I noticed that he has perspective to politicians that what they doing wrong, they are wrong, but I seem he speak a lot about politics, OK. But he also being little rude even when he was telling an incident he used some 'rude' about politician. So when I tell this to my uncle he said 'When he's monk he should not be rude to someone or harm even by "Kaya (Body/Physically)", "Vacha (Talking)", "Man" (Mind/Thinking)'. So does it break first precept? If you caught me doing wrong(Killing, Stealing, Inhumanity) and if you make specific perspective to me for lifetime does it break first precept? Thinking wrong about someone else for what it is (Thief, Terrorist, Murderer).
It certainly doesn't break the Vinaya rule against killing (which says it doesn't count as "killing" unless somebody dies, plus other conditions).
I expect your uncle is right to say that he should avoid being rude; and even talking about politics at all could be considered questionable behaviour.
I haven't seen any hint, though, that the first precept isn't meant to be taken iterally; for example:
pāṇātipātā veramaṇī：'abstaining from the killing of living beings'，is the first of the 5 moral rules binding upon all Buddhists
If the behaviour is wrong I don't think it's because it breaks the first precept -- instead I think it would be because it's not Right Speech, or something like that (e.g. not friendly).
Does perspective to someone else break first precept?
(for example in a way of words or signs: "It would be good if he is death", "Better they would not exist"...)
Just because nobody seems to answer use- and helpful, and only in short: Yes, if certain factors are fullfiled. As for a monk doing such and certain factors are fullfilled, it a Pārājika, meaning he is no more afflicted with the community and has lost his possibilities to live and practice within the community. (Think on certain monks spreading hate speech and certain people act on that, or others, telling "its no problem to kill an embryo", people act on it... just to give samples to think.) In reagard of kamma, thoughts are plenty enough to have effects. So take care in all, body, speech (incl. signs, gestures, writen words, drawings... and all other kinds of communication, even mental if one is able to) and you thoughts.
One might know where to ask if serious more interested. (Note: This is a gift of Dhamma and not meant for commercial purpose or other wordily gains.)
Your uncle is right 'When he's monk he should not be rude to someone or harm anyone by "Kaya (Body/Physically)", "Vachi (Talking)", "Mano" (Mind/Thinking)'. That monk does not follow Nobel Eight Fold path to "Nibbana"(Enlightenment). Does he break first precept? No. But he breaks the Nobel Eight Fold Path to "Nibbana". Theravada monks are promised to "Sabbadukkha,Nissarana,Nibbana,Sacchiaranatthaya" (For the realization of Nibbana, the deliverance from all sorrow) in the ordination procedure which is directly related to follow Nobel Eight Fold path.