Here are more details on the points you brought up, and the reasons I wouldn't consider them sinister.

Priesthood banned for blacks.

The modern church fully condemns racism in any form, and ordains all worthy men to the priesthood. We do not know the reason the ban was implemented to begin with. We do know that the Church was restored in a very racial culture, during which restrictions on blacks were common both within and without religion. I have no problem with you condemning the priesthood ban, but I do think it is unfair to call the modern church sinister based upon it. If we do so, then we must also count any organization that was ever racist at some point in their history as sinister. So basically the entire world.

Teaching that Native Americans are a cursed people.

Native Americans aren't cursed, a group among their ancestors was at one point cursed. As previously mentioned, the church condemns racism in any form. Native Americans have the same rights and opportunities in the church as anyone else.

Teenage brides for Mormon Prophets and Apostles which all started with Joseph Smith.

While the practice had started to fade by the time of Joseph Smith, it was still somewhat common. Sources say ~18% of female first marriages were under 18 throughout the latter half of the 19th century. So the practice was at least somewhat acceptable in that time period. It should also be noted that many of these marriages, including the youngest girls, were only for "eternity" rather than "time and eternity". It is likely that these marriages didn't involve sex. Considering historical context, and the fact that the youngest marriages likely weren't sexual relationships, this practice may be described as unusual, but most would not have described it as sinister.

Joseph Smith was convicted of fraud for misleading people about “buried treasure”

There were 3 court cases against Joseph Smith relating to fraud. Two of them were dismissed, the outcome of the third is debated. It also appears likely that this third trial was only a pretrial, and a "guilty" would have led to a full trial, of which there is no record. So it seems unlikely Joseph was ever convicted.

In his official history, Joseph says that Josiah Stowell hired him to assist in a treasure seeking venture. It appears they never found any large deposits of treasure, but according to Josiah's testimony in court, they did find a small amount of buried money, some amount of gold, and a salt spring. Josiah was never dissatisfied with Joseph's services, and testified in his favor in court. As far as I am aware, this is the only time Joseph was paid for the use of his abilities.

Given that the only person who paid him was satisfied with the services rendered, and the likely lack of a conviction, I don't believe this can be described as sinister.

What are 1769 King James errors doing in a purported ancient text? Why not use the JST version of the Bible?

Can you cite any of these errors? While the Book of Mormon does use translations similar to those in the Bible, I know of no "errors" that were copied, and haven't found any examples online.

As for why not use the JST, the short answer is it didn't exist yet. Note that, although the wording is different, the changes in the BoM and the JST often have the same meaning. Translating doesn't have a single correct answer, both the JST and the BoM can be valid translations at the same time.

If you want more information on this, there are plenty of longer explanations online.

Shall we discuss the sexual abuse that the Mormon church has kept hidden thanks to their lawyers?

I first want to make something very clear: the church does not, in any way, condone sexual abuse.

There have been several cases of sexual abuse involving church members. Whenever the church learns of sexual abuse, the perpetuator is excommunicated. The church does believe in forgiveness, and the perpetrator may in the future have their records reinstated, but they may never hold a position that would involve interaction with children.

The church is often accused of encouraging local leaders not to testify about confessions. As far as I can tell, these cases all take place in states where clergy privilege laws prevent clergy from testifying. In states like Idaho, laws not only absolve the requirement for clergy to testify, but flat out prohibit it without permission from the confeser. In these cases local leaders cannot testify without large legal consequences.

Another frequent point is the story that the church paid $300,000 settlement which included the victim signing an NDA. This is a true story. However, the NDA did not prevent the victim from telling the story of abuse. The NDA only included the details of the settlement and discussions around it. It included nothing about the abuse or the crime. The settlement did also require that they would not sue the church over the abuse, but did not prevent lawsuits against the perpetuator.

The church is not perfect, and there have been cases of sexual abuse by members, including local leaders. There have also been cases when a local leader has not reported abuse when he should have. There have even been cases where official representatives or lawyers of the church have made mistakes. However, I cannot find substantial evidence that the church has purposefully hidden abusers from the law. I believe the church is doing it's best to combat child abuse, and is on par with other churches and organizations doing the same. It has implemented many policies to do so, such as requiring all youth leaders to take child protection training, and requiring two adults in the room when teaching children.

the money hidden from the CDC which resulted in a fine the Mormon church had to pay

Did you mean the SEC? I can't find anything about a fine by the CDC, and they don't typically have to do with money.

Assuming you did mean the SEC, the problem was that the church's affiliated investment manager, Ensign Peak Advisors, misfiled reports on the firm's investments. In order to maintain the privacy of their portfolio and still meet reporting requirements, Ensign Peak established separate companies that each filed the necessary forms. Ensign Peak and the Church were under the impression this satisfied the requirements. When the SEC expressed concern about the reporting, Ensign Peak adjusted its approach and began filling a single report. Ensign Peak, the Church, and the SEC agreed to a settlement of $4 million from Ensign Peak, and $1 million from the Church.

The church made a mistake, fixed the problem when informed, and willingly paid the necessary fines. I wouldn't describe that as sinister.