I think "laughing" modifies "children"
Answer to the First Question: In order to feel welcome to an unfamiliar place, one must understand its culture - be familiar with the language or dialects, respect its traditions, and overall, have a sense of tranquility and confidence when staying at that place.
Answer to the Second Question: One can educate themselves about the culture of the place by reading books and articles related to the subject, but a quicker and more effective approach to feel welcome would be to socialize with the locals and learn from their stories.
Answer to the Third Question: A person call when they are not welcome if the locals frown at the sight of them. Not getting invited to local rituals or getting secluded from all conversations are also evident signs of disapproval.
Answer to the Fourth Question: Many close-minded people would judge others' tendencies based on rumors, gossips, or popular stereotypes taking the place to which the stranger belongs as a frame of reference. In some cases, people would show respect and welcome anyone regardless of their past history, due to their inculcated manners or social traditions.
Um, I think it is "proper grammar"? Not sure
The main idea of a text is the point it is conveying to the reader. It can also be called the purpose for writing the text.
