2) Are you both committed to being chaste through your engagement (not giving in to pre-marital sex, which can only harm your relationship and take away from both of you the gift of your bodies which the sacrament prompts)?
3) Are you firm about never using artificial contraception within your marriage, nor using NFP as a form of contraception? Being open to life is critical. Spacing children is permitted if there is grave reason to do so, and NFP can help with that, but using NFP for a reason like wanting time to get to know each other or you just don't want any more children when there is no grave reason not to be open to it would be an abuse of the NFP opportunity.
4) Have you talked about raising the children? How you will discipline, educate, and guide them? It is important to be on the same page about these things, but also flexible if life should deal you a hand you did not expect.
5) Do you both know how to forgive and ask forgiveness? You will spend a lot of time unwillingly hurting each other during marriage. It helps to marry someone who knows how to ask forgiveness as well as forgive. Too many marriages are laced with prideful people who don't ever want to be wrong and must blame the other for everything.
6) Do both display proof that your love is grounded in service of the other? Do you tend to each other's weaknesses and needs and see each other's happiness over your own? Mutual love through service can get you through any trials, as well as help your love grow stronger. You are going to have your moments of weakness and need, and it is up to the other to be strong for the other's sake at those times. Also, both of you are inclined to selfishness by fallen human nature, so love for each other and the children that come in marriage is the path to sanctity that is a selfless life. You will both inevitably have selfish moments that threaten the peace, so it is up to the other to bear those moments well, and help the other come out of that selfish moment through gentleness and kindness, as well as firm requests for the higher good. Dating and engagement should be a time of seeing these qualities in action. However you are together now will be carried over into the marriage. So make sure you have plenty of opportunities to be challenged to love each other in selfless service.
7) Do you both have God and His Church as your point of reference for what you believe and how you live your life? This is tremendously important when it comes to resolving problems. Having God and the Church as the authority allows both partners to help identify what is right and wrong about the situation and in the actions of each, and help to know who should be sorry for what. But keep in mind that it is always a call to heroic virtue in marriage to admit you are wrong when you are not, for the sake of the other who might be too crippled in the moment to admit they are wrong. That is an act of charity on your part, and charity is always the highest form of living true love for another. Resolve the situation later, make the peace now. But do resolve it. You are not a doormat for the other to take advantage of because you are so generous and kind and charitable. Marriage requires both to be working on themselves in order for it to be a success. One doing all the work is just a bad marriage that is being endured, specifically by the one must do what they have to do.