Seer stones
Read your OT again and notice how many time stones are used by God to communicate something. Also each of those that enter into the Lord's presence will be given a white stone
with a new name on it.... (Revelations 2:17)
So stones have been used by the Lord in the past, and in the time of JS. A lot of people do not know this, so it can be confusing.
The Book of Abraham
The interesting thing about the Book of Abraham is that JS made some interesting interpretations of the facsimilies that came with the BOA. Many Egyptologists do not believe that JS interpreted correctly. These are the people that you have chosen to believe. Rather than your prophet and other Egyptologists that agree or partially agree with JS.
You have to remember that Egyptology is still an ongoing study. It is very difficult to know exactly what 300bc Egyptians were trying to say in their writings, let alone going back to 2000bc.
Is what JS said plausible. Many say yes, many say no. Study those that say yes and you will be better served. If you are going to doubt, why not doubt those say no, instead of those saying yes. The jury is still way to out for anyone to say this is false.
The church's racist doctrine...
Are you a Democrat. In fact, are you kidding. You were born after all men were given the right to hold priesthood. For the last 40 years all men have had the right to hold priesthood. In fact one of the largest areas of growth for the church is in black Africa. The church is all in and there is great work being done by all colors of people
throughout all the world. The church is the model that should be used by governments to mesh people of all colors in a great cause of witnessing to the world of Jesus Christ.
If you want to stay in the past and doubt the fuzzy past, do so and you will get left behind by all the colored folks you feel sorry for, who have the blessings of the priesthood and now you do not.
Polygamy and Polyandry
Polyandry has never been proved. JS did marry a few women that were married at the time to other men. However, JS marriage to them was for only "eternity". Not for "time and all eternity". "time" = "this life", "and all eternity" = "after death".
So JS marriage was for after they died, then they were married to him for eternity. So they went back to their husbands and lived out their lives without any sexual relations with JS, and when they died, then they were a wife of JS.
Polygany was a blessing to the church. It was able to grow exponentially and quickly became a nation in less time than usual. This nation then was able to defend itself, create its own economy, take care of the women who lost men in persecutions, create a missionary force quickly, etc., etc., etc.
You again are listening to the wrong people. Doubt what they say, not your prophet and leaders of the church and the actually facts about polygamy. Did some men abuse their relationships, yes, but those few can not be the examples you question. Look at all the hundreds of men and women who live the way the Lord wanted them to live at the time. Who brought to pass the word of the Lord and brought to pass a desert empire that is reaching around the world and declaring Jesus Christ is coming, prepare and repent and be ready for his second coming.
also read the OT and all the people (prophets, kings, priests, common men and women) that practiced plural marriage. The Lord allowed polygamy then, for the same reason he allowed JS and the church members to practice polygamy today. To grow a nation to the Lord, quickly.
The Kinderhook plates
Read the story from an LDS writer, and you will see how stupid this story really is. If you read it from an anti side, they tell a whole different story that is just not true.
Again, doubt the anti, do not doubt your religion.
I have looked at all of these examples you have given me many, many times and have remained faithful in the church because I doubted what they said, rather than my prophet and leaders and authors and researchers on our side. Do the same.