I've been happily married for several years. I stay married for many, many reasons. So I didn't mark off anything in the pole. My husband is my friend, lover, and partner in raising our kids. And, we both love the Lord. I can't imagine life without him. It is sad to see so many marriages destroyed today. The messages that the media bombards our homes with about marriage are very evil. That's why I especially liked your suggestion in #3:
3. Have realistic expectations: We are more likely to remain in a marriage when we have realistic expectations of what it is to be joined to someone.
People get married thinking that life will be full of bliss and happiness. That in perfect marriages, couples never fight. That a perfect match includes someone who will always agree with you. And, if it all doesn't pan out, you can just get a divorce. No problem. It's all hogwash.
On the contrary, in a healthy marriage, couples disagree and even have arguments. If they don't, something's wrong, because that means they are no longer communicating. I even postulate, that disagreements help a marriage to grow, because you learn more about each other and how to treat each other, and you grow as a couple because of it. The trick is, learning how to fight fairly with one another. This, my husband and I have learned to do pretty well. That's why we are able to stick together and our love grows more strongly over the years. If you can have a disagreement without accusatory tones or words and with intentions to resolve the matter in a mature, adult manner, you're on the right track.