You have to reduce karma to numbers to fully explain causes and effects of karma. Karma is the sum total off all the things a person has done, in this life and in previous lives, on-purpose or accidentally, which has caused or prevented suffering of sentient beings. Karma can be changed by one’s actions. People with very good karma or very bad karma emanate karma that affects people around them. Objects and locations also have karma as well and follow these same rules, but with some differences. When people’s thought/words/actions cause suffering to happen, things will tend to happen that will cause them to suffer. Similarly, if people reduce suffering, they will tend to have good things happen to them. Karma is like a magnetic field: it is an invisible tendency that draws good or bad things towards a person. Karma doesn’t exist just in sentient beings. It can build up in inanimate objects that were used to create or ease suffering. Karma can even remain in corpses or even build up in Pearl-like concentrations (product of cremation of people with high levels of good karma, dark Pearl-like if bad karma instead). Karma can spontaenously form into a sentient being. This being leads to a series of successive incarnations after being an initial karma being for a short while.
Karma in numbers (example purposes only as I don’t really know the math but will apply numerical value to acts) 1: cause vice or help someone overcome vice, hinder or help a holy person, steal a person’s possession or give a gift, tell a lie or tell the truth, insults someone or complement someone 2: destroy art or create art, cause hunger or feed hunger, steal from a monastery or donate to a monastery 3: turn into a killer or help a killer reform, mutilate someone or prevent someone from being mutilated, destroy or print a common holy book, dissuade someone from going on a pilgrimage or make a pilgrimage to a holy site 4: cause an illness or cure and illness, kill an animal or save the life of animal, torture a being or save a being from torture 5: cause a person to break a vow or cause a person to take a vow, kill a human or save a human, destroy or save a rare holy book, convert someone from Buddhism or convert someone to Buddhism, free someone of an oath to do good or bind someone to an oath to do good, bind someone to an oath to do bad or free someone of an oath to do bad
Karma is effect of one’s actions, words, and thoughts. Karma is the same whether you do it to yourself or do it to someone else. Even things that only happen in the mind contribute to karma. Future karma is based on the future effects of present actions counting as if you did it then. Some actions bring about mixed karma. Karma is relative to culpability. Karma can be either deficit (bad karma has negative value) or surplus (good karma has positive value). Helping or hindering Buddhism will have an especially strong karmic effect. Since Buddhism is the way to enlightenment and the permanent end of suffering, Buddhism related act have a karmic multiplier attached to them basically.
Karma and one’s life also depend on what type of sentient being one was born as. Devas, Asruas, Humans, Pretas, Animals, and Narakas all have differing karma to be born there and different likelihood of their karma manifesting in various ways.
Natural karma negate the karma from existence while karma caused by another sentient being gives the causer karma while the effect person’s karma has been fulfilled.
Your analysis was anthropometric as it has only focused on suffering in humans. All acts are good or bad to a finite extent. To say that noting could equal in value to something, is to claim that the good or bad value of something is infinite which is impossible logically. Fairness/proportionality and liberty are respected by karma as people have liberty to sow good and/or bad causes as they see fit, but they must reap the consequences. Also, effects are fair and proportional to the causes. Use my number guide as an example of proportions. Say any person has a karmic tab from their current life and at least seven previous lives all summed up in either a negative or positive number. Even if the number if negative on average, positive karma can still assert itself. This goes inverse as well, even if the number is overall positive, negative karma can still assert itself. Karma is all in the numbers. No suffering is unbalance able, because that would make suffering infinite which is impossible. For examples, Buddhist sutras show examples of various sufferings by various individuals with Buddha explaining their causes on various occasions. To point to any type or amount of suffering as disproof is an appeal to emotion where you didn’t logically measure the suffering and just feel that the suffering has infinite value and that no amount of past or present bad behavior could justify it happening. Logical thinking is cognitive, not emotional. This is why appeals to emotions aren’t valid arguments.