A: Yes, what you've related would be unfair if it were true. I know many people suffer from the burden they believe the departed have placed upon them. In some cultures people die because of their belief that those who've departed can influence them so profoundly, so it's not a problem to be dismissed lightly.
Our minds are powerful influences and can perform amazing things, some hard to believe. Having powerful minds and the free will to direct them however we choose is a birthright we all are endowed with. Some people are willing to turn over the control and function of their minds to others--the others don't have the capacity to control a healthy mind without the willful consent of the person being controlled. So, yes, some people can and do suffer from someone else's misdeeds, but it is a choice they've made, perhaps unconsciously, to do.
The Urantia Book has the most complete and factual information about the birth of the soul , how it functions, what it does, where it, and we, go upon death, and what the life hereafter will be like. There's a short presentation on our site titled After You Die that should be of comfort to you and help answer your question.
Briefly though, the answer to your question is no, departed souls do not physically or mentally affect us--they leave earth and are involved in activity that's meaningful to their own development and are not involved in any further activity here on earth; they do not return. Energy patterns and mindal energy systems that had been part of that person's makeup while alive may still exist once the individual is gone--sensitive people can tap into those energies or even those not so sensitive can as well if they choose to. It's a matter of free will choice whether one wants to indulge in these undertakings or not; they can as easily be dismissed and disregarded, whether they're real or not.
Do we pay for the misdeeds and sufferings of our ancestors? Only if we choose to aim our minds in those directions--yes, some people do suffer from such perceived burdens, but again, it's their choice to do so, whether the choice has been made consciously or unconsciously; such choices can be reversed by refusing to entertain thoughts along those lines. Even in the case of the Lucifer rebellion, which has affected the entire planet, and under which some still suffer, we still have the power of choice. We still have the capacity to choose eternal life . We still can overcome those effects through our own determination and faith. Our Father in heaven does not burden his mortal children; we are not held accountable for another individual's actions--it's only our own actions that matter. Just as the Father did not require an innocent sacrifice in order to appease wrath, neither does the Father require that we pay for the sins of others--it's our choice if that's what we choose to do. Jesus has exhorted us to fear not; trust Jesus."