That makes me revisit the big Question "Is SDA a Cult?"
No, they are not.
They are a very regular protestant church except they go to church on Saturday and not Sunday. They also have an extra, extra, extra dose of anti-Catholicism beyond the usual dose among some protestants. This is because Ellen G. White told them that the end times will consist in the Catholic Church establishing a "sunday law" which it will use to persecute and kill Adventists for not worshiping on Sunday. Anti-Catholicism is therefore a central part of their belief system in a way that it is not in other churches. I believe the Pope has 666 somewhere beneath his mitre on his head, per the best SDA wisdom, and his non-existent title (vicarius filii Dei) is supposed to add up to 666
They also follow some dietary laws from the old testament and some extra additions, like not eating meat and sticking to vegetarian meals. They have Pascha (Easter) not on the regular Easter but on three/four designated times a year, i think every three/four months. They do the whole shebang, washing each others' feet and wiping them and the last supper. I think its a lovely practice.
They don't celebrate Christmas (At least not in church, anyway....at home, its a completely different story
). They have a week long camp every year--it has a special name but I forget. SDAs take hymns very seriously and they do their singing very well. When they visit each other at home, or in the Hospital, they will always do a prayer and a song and the songs are always lovely. As you are now aware, they also believe in soul sleep and they believe that St. Michael the Archangel is not a regular angel (creature) but rather Christ.
Those are the only peculiarities about SDAs that set them apart from others. Besides those, they are really much like any other protestants. Not weird at all.