I'm currently a 5'9'' 160lb potato faced subhuman and probably at 25% bodyfat (eyeballing it here). I don't really care about how my body looks too much, what I want more than anything is to just get rid of my facial fat and see what my facial bone structure is actually like (and start planing on what surgeries I need). I started limiting my calorie intake to 800 last week and assuming I lose 4lbs of fat for every lb of muscle, I should be able to reach 10-11% by losing 30lbs sometime in July if I can keep this up (gigantic fucking if, I know). Assuming I do manage to keep up the deficit:

Am I way underestimating the amount of muscle I'd be losing? I've been googling for a bit and getting mixed results. Some people are saying your body will burn fat the most easily and muscle loss will be minimal, while other say that muscles will the first to go because they require more energy to maintain. I'm guessing exact ratios are impossible to determine but which is closer to the truth? Don't have much muscle to lose to begin with, but it would take much longer to reach my goal if most of the weight I lost was muscle as opposed to fat.

How much facial change can I really expect? All the progress pics I've seen are people going from fat/obese to skinny and while they're faces have been completely transformed, they also started out with a LOT more fat than me. There are understandably very few ones with someone skinnyfat of my size going to skelly mode.

The r/fitness wiki says starvation mode is just a myth, but I've always been told that your body does in fact start to lower you bmr if you restrict your calories too much and for too long. Is this true and by how much would this affect my weight loss if so?