2. Keeping in view that the word "Israel" means God's servant and the word God is mentioned in it, albeit in a non-Arabic language, is it necessary to touch it with Wudhu? Sometimes, this word is painted by people on roads to protest against Israel, is it not haram to step on it intentionally?
3. If a word means "God" in one society and the same word means something else in another society, how should one go about it? What is the Islamic law in this regard?
4. If a person's name is Habibullah, should he touch his own name with Wudhu? Does the rule concerning holy names apply to his name?
It is haraam, as an obligatory precaution, to touch the Name of Allah, without Wudhu, in whichever language it may have been written. And it is also haraam to touch, without Wudhu, the blessed names of the Holy Prophet of Islam, the holy Imams and Hazrat Fatima Zahra (peace be upon them).  As for names which contain the name "Allah" (either as a prefix or as a suffix) like "Habibullah", there is problem (Ishkaal) in touching "Allah" without Wudhu? 
However, the word "Israel' in Hebrew means someone who under God's control, contrivance and servitude. Thus, it gives a meaning close to "Abdullah" in Arabic.  In any case, the word "Israel"  is the title of Ya'qub son of Isaac son of Ibrahim. It is necessary to respect this word in ordinary situations and when the word is considered all by itself. However, since this name is the standard for combat against Islam and it is a sign of animosity with Muslims, therefore, there is no objection in touching it and stepping on it deliberately to condemn and protest the enemies of Islam. 
In regards to the foregoing questions, Ayatollah Mahdi Hadavi Tehrani's view is as under:
Answer 1: It is haraam to disrespect God. Therefore, if a person does an action which is considered to be disrespectful and an insult to God, it is haraam. But if an action does not have such an implication and the person doing it does not have such an intention, it is permissible. Therefore, if a person touches God's name without intending any insult and it is not considered as an insult by people either, it is permissible, thought it is makrooh and the precaution is to avoid doing such an act. The position is the same with names of prophets, the Imams and Fatima Zahra (peace be upon them).
Answer 2, 3, 4: The answer to these questions can be obtained from the answer to the first question. Of course, in regards to the third question, it should be noted that the criterion is the Urf (custom) of the wise or the custom of the same society in which this action takes place.
 - Tawzih al-Masial (with annotation by Imam Khomeini), vol.1, pg. 187; extracted from question 19034 (site: 18453) , Index: Touching the Script of the Quran without Wudhu.
 - Ajwebat al-Isteftaat (Farsi Answers to Religious Questions), pg. 31, Question 152: What is the Islamic law about touching names like "Abdullah" and "Habibullah"? Answer: It is not permissible to touch the word "Allah" without Wudhu even if it makes a part of a compound name.
 - Al-Tahqiq fi Kalimat al-Qur'an, vol.1, pg. 84,
"أنّ معنى هذه الکلمة فی اللغة العبریّة یطابق ما قلنا فی مادّة أسر من العربیّة، فمعنى إسرائیل: من یکون تحت النظر و التوقیف و التدبیر و الأسر من اللّه تعالى، و هذا المعنى قریب من کلمة عبد اللّه."
 - See: Ali Mahmudi, Bani Israel.
 - Oral Isteftaa from the office of the Supreme Leader (grand Ayatollah Ali Khamenei) – may Allah grant him long life.