I have three case scenarios here:
Please accept this (gift/money as an) appreciation.
Let me treat you a meal!
Join our team!
As far as I know, in the first case, rejecting the offer is rude by any mean/for any reason. Nonetheless, in the second and third cases, many factors, other than personal will, can play a significant role in the decision of whether to accept the offer. For instance, one may have already planned out his schedule of the day and cannot allot time for socializing. Yet, it seems to be rude to directly reject the offer regardless of the reason. Is there a proper way to reject these offers, especially when the person who gives the offer is more superior in terms of age or social status? What are some possible replies to these offers?
By the way, if I have any improper cultural statement(s), please point it out!
Thanks in advance.