Is it permissible to reject a suitor who is not a financial or cultural match? And am I sinful for doing so? And is it permissible to reduce conversation with relatives who engage in backbiting and slander, without that affecting my good deeds?

There is no harm in rejecting suitors who are financially or educationally unsuitable, as considering these matters is good. However, excessive rejection and exaggeration in conditions are not without consequences.

As for upholding kinship ties, it is obligatory to maintain ties with one's maternal aunt and other relatives. The rights of the maternal aunt are great, for she is like a mother. If some relatives engage in backbiting and slander, one must avoid these forbidden acts and strive to steer the conversation towards good and advice. If backbiting occurs, it is obligatory to denounce it, clarify its prohibition, and change the subject. If that does not work, then one must avoid the gathering. This does not necessitate complete boycott, but rather mixing in matters that do not involve sin, and showing kindness and benevolence to the maternal aunt in matters that do not involve disobedience. One should also frequently supplicate that Allah bless you with a righteous husband and help you obey Him.