1.a. Moksha is not necessary. Rather, it is a natural urge that people get when they observe the impermanent nature of all works and all pleasures. When a person gets to the stage of wanting to no longer participate in this seemingly perpetual cycle, our system provides a path for that person to get released from it.

1.b. It is not necessary to remember your past life or your previous karma. All you need to know is that there is a mix of good and bad karmas that are bearing fruit in this life. The good ones give rise to pleasure and the bad ones to suffering.

1.c. Each life is indeed a fresh start in terms of memories and experience, but the past karmas have made an impression on your psyche at birth so that you are already carrying the effects of the past in the form of "vaasana" or dispositions. They affect your personality, outlook, and psychological/behavioral traits.

2.a. The soul is not “reborn” as it implies that the soul was born in the first place and also died at some point. Rather, when the soul + subtle body unites with a physical body, it is called birth, and when the soul + subtle body separates from the physical body, it is called death.

2.b. The mechanism of karma is not fully and consistently described and needs to be pieced together from scattered sources. On the other hand, it is not relevant to know the mechanism as you have little control over it. To put in control theory terms, it is neither fully observable nor very controllable.

2.c. There is controversy about where the karma is actually stored or recorded. Some ascribe it to the subtle body, others to the soul, and others to God.

2.d. Your consciousness at the time of your death determines the next birth.

3.a. If someone lives a good life and still suffers, it might be due to karma or due to foolish choices that the person makes. Good people also sometimes make bad choices in this life itself.

3.b. There is no empirical verification of karma and samsara. It is a model that is used in Hinduism, Buddhism and Jainism to explain life. Hindu scriptures are the sole means of proof of this concept. That doesn’t mean that you need to take it on faith, but you can reason about it to get a cogent model in accordance with scripture.

3.c. The free-will/determinism debate is extensive and needs dedicated space.

4.a. Dharma is defined by shastra.

4.b. Conscience is a product of culture, learning, upbringing, personality and a host of other factors, and cannot act as the sole guide for righteous action. It should be obvious that the conscience of malfactors gives them poor to no guidance, otherwise they wouldn't be engaging in their malfeasance. And given the prevalence of bad actors in the world, it is no way reliable. And in case you're tempted to say that "but I have a good conscience; not like all those bad folks", you're kidding yourself.

5. If you don't have a spiritual longing, that's fine. Simply follow a dharmic path. A spiritual longing may arise in this life at some point or in some future one.

6.a. Moksha requires conscious and intentional application. It is seldom a default, unless the spiritual progress in your previous life was intense and your life came to an end before you attained moksha. In that case, you will be born with the requisite mental disposition to pursue the path right away.

6.b. Because mumukshatva (desire for moksha) is conscious, you will know that you're making spiritual progress by observing the changes in your attitude towards your life, the world and the universe. You will know without any visible markers because you will experience the progress directly.

7.a. It is useless to inquire into your previous births. What matters is how you act now. The rules are clearly stated in the shastras and you can figure them out by learning them. It is pointless to know which of the rules you transgressed in the past. That said, it may be that some sages can have insight into their past lives. But again, such knowledge has little practical merit.

7.b. Your body and mind are meant to cope with your current existence. They provide you with the tools to survive and flourish now. Nature has no interest in your spiritual aspirations.

8. If you are asking all these questions, then you already have a deeper push. The vast majority of people go around their work-a-day lives without bothering with any of these issues.