That said, I think most mormons take the good out of the religion and don’t pay much attention to the nuttyness. I don't know what you would define as "nuttyness", however mormons are encouraged and expected to make regular visits to their temples in which they perform secret rituals to baptize the dead of any and all faiths in order that the dead may become "worthy" to reach the "exaltation" believed in by themselves.
This is a very important part of mormon culture.
Other temple rituals include performing marriages for "time and eternity" which is also a very important part of mormon culture.
Admittance to their temples is only allowed to those who are deemed "worthy" enough to gain a temple "recommend" which is provided after the following interview:
Here is a list of works Mormons must perform in order to be “worthy” to take part in the Temple “endowments” and “covenants.” You will be questioned by your Bishop or Stake President in order to be deemed “worthy.”
1 Do you have faith in and a testimony of God the Eternal Father, His Son Jesus Christ, and the Holy Ghost?
2 Do you have a testimony of the Atonement of Christ and of His role as Savior and Redeemer?
3 Do you have a testimony of the restoration of the gospel in these the latter days?
4 Do you sustain the President of the Church of Jesus Christ of Latter-day Saints as the Prophet, Seer, and Revelator and as the only person on the earth who possesses and is authorized to exercise all priesthood keys? Do you sustain members of the First Presidency and the Quorum of the Twelve Apostles as prophets, seers, and revelators? Do you sustain the other General Authorities and local authorities of the Church?
5 Do you live the law of chastity?
6 Is there anything in your conduct relating to members of your family that is not in harmony with the teachings of the Church?
7 Do you support, affiliate with, or agree with any group or individual whose teachings or practices are contrary to or oppose those accepted by the Church of Jesus Christ of Latter-day Saints?
8 Do you strive to keep the covenants you have made, to attend your sacrament and other meetings, and to keep your life in harmony with the laws and commandments of the gospel?
9 Are you honest in your dealings with your fellowmen?
10 Are you a full-tithe payer?
11 Do your keep the Word of Wisdom?
12 Do you have financial or other oblgations to a former spouse or children? If yes, are you current in meeting those obligations?
13 If you have previously received your temple endowment:
Do you keep the covenants that you made in the temple?
Do you wear the garment both night and day as instructed in the endowment and in accordance with the covenant you made in the temple?
14 Have there been any sins or misdeeds in your life that should have been resolved with priesthood authorities but have not been?
15 Do you consider yourself worthy to enter the Lord’s house and participate in temple ordinances?
Note that in the case of couples being married in the LDS temple, ONLY those witness or family who have a temple recommend are allowed to be present at the wedding ceremony. Those who are not "worthy" are required to wait outside until the ceremony is over, and then may take part in the wedding pictures.