When dealing with requests from individual students (eg grade grubbing), remember it's not just about being "nice" or "mean", it's about being fair to other students

In a vacuum, a lot of professors may feel guilty about rejecting requests from invididuals because it makes them feel harsh or mean. But the important thing to remember is that being kind to that individual student is not necessarily being kind overall. Academics are often akin to a zero sum game, so rewarding one student is punishing all others.

Giving a few points back to a student who argues for them is indirectly hurting the students who made similar mistakes and accepted their score. You don't want to put a tax on students who just put their head down and don't make a fuss.

Rescheduling things for a student's family vacation is unfair to students who may have turned down similar situations with their families because they knew they had class.