Interesting story, sorry it turned out so difficult for you but as you said, much to think about and learn from.
Promises and rules mean different things to different people... My take, for what it's worth: Rules that are fairly negotiated are easier to keep. Sometimes a rule that's been broken shows that it wasn't a workable rule to begin with. Sometimes we put rules on other people that we may not really need in the end (because we don't know ourselves totally). What we do need, usually, is something more vague ("I need to feel safe" "I need to feel like you respect me") rather than needing to you to specifically do certain things. For me, I have both broken rules and had them broken on me, and when the relationship is a good one we can communicate through it.
I guess it depends on whether you can trust another person, recognise that they're wanting to be good to you, wanting to be trustworthy and trying their best. I don't expect perfection from myself or others.
Wish you easier experiences in the future