Buffet or plated? Meh, I don't really care as long as there's enough food that I won't have to go hungry.
Open seating, place cards, or escort cards? Cards one way or the other. Open seating means you need to have about +20% more chairs than people, because people won't fill up tables neatly. I much prefer to know at least what table I'm supposed to be at.
Buffet, I like to choose what I want and I find the quality of the food to be generally better (in my experience). Plus years ago I worked at a hotel and experienced first hand the chaos of the kitchen in getting 100+ plated meals out at the same time. If you have seen what goes on, you probably wouldn't think a plated meal is less "germy." Served buffets are nice too.
Assigned tables, but not seats. Or assigned seats and tables.
I prefer plated (too lazy to stand in line). And while I feel assigning guests to a particular seat is unnecessary, assigning table is an absolute must (unless you're having like fewer than 30 guests).
I'm glad to see guests like assigned tables. I felt like it was like being in school again and didn't want guests to feel that way. I've been to a ton of weddings but only 1 was plated so not really sure what I prefer. FI has no preference either.
I prefer plated because I hate having to rush in line. I know you might still "wait" to get served when it is plated, but at least, you are sitting while you wait
and I prefer escort cards. I like to have a spot that I don't have to search for to be honest
Plated and escort cards. It's nice to put people together with people they know, but let them choose which seats at the table to take. I also just feel like plated is more elegant and you don't have to worry about lines or being told exactly where your table ranks on the priority list of who gets to eat first.
Re: Dinner style and seating
Escort cards. Just assign people to tables and let them pick their own seat.
I like assigned tables but not assigned seats.
I hate carrying around heavy trays of food and looking for unoccupied seats.