The more I think about it, the more I'd love to be invited to such a party.
The Mormons don't have any oddball ideas about Christmas. Sounds like they're just playing Christmas music sung by the Mormon Tabernacle Choir. Heck, lot's of people buy those CDs, they're GOOD.
Shoes? Not a Mormon thing. I've had some folks have me take my shoes off, most don't.
Yep, Mormon theology strongly discourages alcohol, tobacco, drugs and caffeine. Not that it matters much to me, I can't drink alcohol now anyway, maybe never again. By that time of night I'm done drinking colas.
So you just have a social evening, listen to some music, eat a bit and maybe play with some trains. Sure beats getting sloshed or driving on roads where others are doing the drunk driving thing. Doesn't sound like they're pushing you to watch a video trying to convert you. BTW, they DO make great videos. Seen a few. If you get a chance to watch one on touring the inside of temples, take them up on it. Those places are gorgeous on the inside. Always high production values.