Ok,
I will try to be more direct Apollos. But for this to do any good you need to bring down your defenses for a little while. It is difficult to have a discussion with someone who has their fists up to hit you before you have said anything.
Question: Are Mormons Christians?
Answer: I don't know. They do believe they are because they believe their church is founded, not by Joseph Smith but by Jesus Christ and that Jesus Christ continues to direct the church to this day through a prophet that Jesus himself selected. Hence the name "Church of Jesus Christ of Latter Day Saints".
Question: Do the Mormons believe in historical orthodox Christianity?
Answer: Since I don't know what "historical orthodox Christianity" is, it is difficult for me to answer this. I would hazard to say that they believe some parts of it but not all. See the following answer for more info on that.
Question:Do Mormons believe they are the ONLY Christians?
Answer: No. They do believe that the Mormon religion is the COMPLETE gospel of Jesus Christ. They believe that all other religions have pieces of the the gospel of Jesus Christ but not the full gospel. If that feels like we are bashing you, I am sorry, it is just what they believe.
Question:Did Joseph Smith pull out a gun and shoot some mobbers?
Answer: I don't know.
Question: Did Brigham Young say there was life on the Sun?
Answer: I don't know.
Question: Did the LDS Prophets say other dumb stuff?
Answer: Probably.
And I will say this again....I, personally wouldn't care if they did. Their positive works far outweigh the negative in my mind.
Accepting the Mormon religion is not all about what fits into a logical, nice package. It includes personal revelation and faith. There are many logical pieces and some pieces that require a lifetime to understand. It may be in your discussions with Mormons that they may not have had the answers that you seek because they too are seeking those answers. It is difficult for many people to just say "I don't know", especially when it comes to their religion.
This type of response is very typical of topics such as the Prophets, Polygamy, Mountain Meadows Masacre etc. Most Mormons are seeking answers to those things as well. Mormons are very passionate about what they believe in too. Their belief comes from very personal resources and it is difficult to communicate a feeling to somebody else. It is like trying to describe red to someone.
If you have any other questions to ask, Apollos or anyone for that matter, I will do my best to respond as directly as I know how.