Here are my predictions.
Cade Yeager - He'll definitely live.
Tessa Yeager - Main female, so she's safe.
Shane Dyson - He'll live to see another sequel.
Joshua - He could live, but I kinda think he's gonna have an heroic death trying to help save earth and the autobots, he at first was against.
Harold Attinger - I think he might die. Didn't work out to well for the last main human villain.
Lucas - Comic relief character in a Transformers film, odds are he'll live for sure!
Darcy - She's a bit of a wild card. She could live, she could die. I'm leaning towards live if anything.
Savoy - I kinda think this jerk will live. He could die and I wouldn't be too surprised, but I just have a weird feeling he'll live.
Su Yueming - I think she's going to die. I have a feeling she we'll be responsible for creating all those Vehicons in China. Would be nice to have her answer for crimes in a nice explosion.