Q: I am curious what you believe:
1) Allowing a lot of freedom or having a handful of core principles?
2) Written in stone or open for discussion?
3) Forgiven if crossed or held onto for future reference?
4) Shared with others or kept private?
A: 1) You should have complete freedom to discuss and explore what aligned behaviour and core principles would look like in your relationship. Having such principles allows for conscious communication and creating (flexible) boundaries through which the relationship can flourish.
2) Open for discussion. The purpose of relationships is to help us grow in love, kindness, compassion, and acceptance. This means that our so-called negative patterns are often brought to the surface and revealed, and there should be enough love and freedom between you to allow for that to happen. The person whose patterns have been revealed should then feel held and supported through the process of healing those patterns.
3) The way to heal the patterns is to face the thoughts and feelings behind them (on your own or with the support of your partner) in order for the sense of lack, or ego, that they come from to be recognised and released. Once the underlying cause has been released, in most cases the patterns drop away. In some rare cases, it may be that the behaviours remain and are indeed coming from a place of Love. Since they are caught early on and released, this question falls away - there is no need to forgive or hold onto specific past situation since it is known that the person has done the best they could to face the sense of lack out of which the patterns are enacted. If it becomes clear that the other person is coming from a place of Love, and yet that still triggers something in you, then it is your turn to explore what arises in you. Ultimately, forgiveness is about fully accepting and forgiving yourself.
4) It is difficult to generalise this answer. Some things should be kept private, and others can be shared. Since aligned behaviour does not look the same for each of us, but rather depends on where we are coming from, it is not possible for someone else to answer this question - you need to go within and feel into what is right for you.