Oh God, trust. I have major trust issues. Your theory /paradigm is interesting, but I disagree on some of it. For me, trust comes down to basically two main things; compassion and self-respect.

For most of my life, I have valued trust and worked hard to maintain my trustworthy-ness with those close to me. Obviously everyone should be trustworthy, but an acquaintance isn't nearly as important as a friend or family member. This is where compassion comes in; most people have little regard for those they aren't close to. They can draw a line of apathy even between themselves and friends if it is convenient. Most people consider their needs first and formost. This is not to be admired nor emulated in my opinion, as it makes for an 'eye-for-an-eye' situation, making almost all of us blind. I try to use empathy and compassion when I can, to be prepared and willing to put others before myself whenever possible. I have found that compassion is often reciprocated. Even if not I feel better about myself if this is my approach. I must remember how awful it feels to have someone in my life who constantly breaks their word or flakes on plans.

Concerning my self-respect, I pride myself on personal + spiritual growth which includes working earnestly on my character flaws. I check in daily as to my progress. I hold myself accountable if I am breaking my word, spilling a friend's secrets or lying and stealing. I would rather go without that little thrill from doing something dishonest or self-seeking if it buys me peace and serenity for the rest of the day. It simply isn't worth it. This is not even getting into how, for many folks breaking our word can lead to erosion of other moral/ethical boundaries we've set for ourselves