Yours is a fair assessment, to be sure. I, like you, have a basic understanding of Mormonism and of how Jeffers FLDS community came to be what it was. And like you - I find the dictates followers were required to abide by to be restricting and obsessive (and some of them, harmful).
But (and this is why I'm such a pain to those who know me!) - can't so many of the things you wrote also apply to mainstream religion? Back in the day, my grandmother and my aunt experienced excommunication from their Episcopal church for getting a divorce. I have Catholic friends whose families have shunned them completely for divorce, homosexuality, etc... because that it what they feel like the church wants them to do and they feel like the church is right.
Leaders of churches try to control the followers - and so has it ever been and still is today. Leaders of churches consider it their Heaven-sanctioned duty to control their followers and some of those methods of control are downright barbaric (if not physically, then spiritually).
My experience is that we only want to call something a Cult when we think the beliefs are just too "outside the norm" of our society. And I hate that - I really do. All the other crazy mainstream church activity that we see - we'll call that Religion, because at least they look like us to a certain degree.
I have never found a satisfactory explanation for how cults differ from churches. It seems to hinge on societal acceptance and I am not down with that.
I believe it's a cult when you are so afraid of defying your "leader" that you will break the law instead. The members of FLDS would openly defy/break LAWS before they would disobey their leader Warren Jeffs. It's a cult when you fear more for your life, security and well being OUTSIDE it than in it and are forcibly isolated from children, parents, extended family, friends and anyone who does not belong to the cult. It's a cult when basic human rights and freedom are denied and you cannot LEAVE . It's a cult when the leaders make ALL decisions FOR you and you allow them to take your children away because your own children do not belong to you, but to THEM. It's a cult when you have NO CHOICES, including the choice to LIVE or DIE (Jonestown, FLDS Blood Attonement). In a cult it may be that you cannot even marry someone you love or dress or wear you hair the way you prefer - but must ONLY obey and follow the dictates of another person who is not chosen by you, but placed in charge of you and EVERY tiny aspect of your life - regardless of you personal feelings. A cult denies ALL PERSONAL CHOICES AND FREEDOM - for you and your children and you are prevented - by force, abuse, threats, kidnapping of your loved ones or coercion or blackmail, from leaving.
A church is something you join (and can leave) BY CHOICE. You have the freedom to follow the dictates or NOT. YEs, societal and familial pressures may be placed upon you - but you still are FREE to make your own decision - and suffer the consequences by choice. The Catholic church indeed places pressure on it's members - they do not condone abortion, birth control, the death penalty or divorce - but they do not FORBID you from choosing to do ANY of those things by FORCE - only by social and moral constraints. And you can indeed be excommunicated and still CALL yourself a Catholic and follow most of their teachings. They don't evict you from your home, take your spouse and children away and dump you in the outskirts of town with NOTHING. If your family and friends CHOOSE not to associate with you because you have left the faith THEY adhere to, again, that is by their personal choice. The CHURCH isn't sitting at their door with guns and preventing you from visiting them, or them from visiting you.
It all boils down to CHOICE. A Church does not require you to donate money, attend services or follow you into your home or bedroom or office and oversee what you do or say there. They don't have spies checking on you to make sure you don't laugh out loud or cry. They don't tell you who to marry, when to marry or FORCE you to have sex or have children. A Church sets guidelines for membership - whether you follow them and accept their tenets is UP TO YOU - and that choice has NO BEARING on the balance of your life. Cults - like Scientology (IMO) insist on controlling your FREE WILL and find ways to infiltrate every part of your life with OTHER MEMBERS to ensure you follow the rules. And there are threats (blackmail) and real consequences to prevent you from leaving. A real Church doesn't care if you are rich or poor, famous or homeless, they care about providing fellowship, support and spiritual support and guidance and inspiration . A real church cares about your soul, not your pocketbook, it cares about your heart, not your obedience to a person. And it certainly doesn't hold any POWER over you that you do not give it VOLUNTARILY.
Faith and a church are personal choices - and despite any insinuations by others - we, here in America, are free to join or not, believe or not, worship or not. We cannot control the actions and behavior of others, only our own reactions to such behavior. Social or familial pressure and even dysfunction are NOT related to a church, but to those people and their own choices. Even the Amish can leave their faith AT WILL and insist on giving their children the free exposure to the "real world" at age 18 BEFORE they are permitted to join the church.... and that is a VERY restrictive faith - even MORE so than FLDS - in dress, schooling, family and even living - no electricity, AC, phones, computers or cars! Their members live their faith BY CHOICE, not by FORCE or ISOLATION OR BRAINWASHING - or by being taught that all outsiders are EVIL INFIDELS. And they certainly don't HIDE themselves away in compounds behind walls/fences with armed guards and force girls to marry at age 14 to a man 40 years her senior who she has NEVER MET. And they don't remove and trade children like party hats either.
And it's NOT a CULT - but the FLDS IS, IMO.
My OPINION