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.