Is it obligatory to repent from each sin individually, with its three conditions, or is one repentance sufficient for all sins, and what should a person do if only two conditions are met and the condition of remorse is not fulfilled?

If a person repents from a set of sins, provided the conditions of repentance are met (abstinence, determination not to return [to sin], remorse), then their repentance is sound and accepted. They are not required to recall each sin individually. However, if the sin involved a right owed to people, then it is a condition to restore that right or seek their absolution; otherwise, they must resolve to restore it whenever they are able.