> I guarantee there isn't a single person in this thread who could tell me what someone's squat form should look like based on their femur:torso ratio and hip/ankle flexibility.
Flat lumbar, stance roughly shoulder width, though exact placement is up to the individual's preference and morphology as long as it doesn't induce valgus collapse. Knees tracking over toes to avoid shear forces on the hinge joint, hip crease to below the top of the knee (which is actually parallel, and is much lower than what people think is "parallel"). High/low bar up to personal preference, whichever most easily keeps the weight over center of gravity. Shoes up to preference and ankle mobility as long as they're hard-soled. Start with box squats if the trainee is having trouble with depth or the hinge. Easy peasy.
The hip hinge and vertical lift-off trained by the squat is an _exceptionally_ important movement - that's the one that'll keep you from needing assistance to get off the toilet in your advanced age. Want to be able to see what's on the bottom shelf of the fridge without twisting your back and neck into pretzel shapes? Learn to squat. Deadlift training is useful literally any time you'd pick something up off the ground, even if it's of trivial weight. You learn to "lift with your legs, not with your back" by deadlifting. I helped a friend move last weekend and every single box I picked up from the ground was the same motion as my deadlift - and my back didn't ache at all the next day like it used to before I started lifting, oddly enough. Want to pick up your kids and not throw out your back? Learn to deadlift.
Squat is a moderately complex lift, but it's no clean and jerk. Deadlift is just learning to stand up properly. Bench press is a _simple_ movement, and teaching it is mostly about teaching upper back tightness. Work in a proper power rack and/or with a spotter and risk is extremely minimal. If you run around trying to max out your bench without a spotter and without any training, sure, you're at risk of getting hurt. Literally nobody in this thread is advocating that.
Can you get injured lifting? Sure. People do. People also get injured walking down the street, picking up their kids, opening soda cans, falling down stairs, and a billion other ways. Even more dangerous is being a sedentary blob who slowly rots away due to cardiac disease. Life is dangerous - but the strong individual is going to be a lot more resilient than the average Joe, and you don't get strong without putting your body under stress - and therefore at some risk of injury, But, as Mark Rippetoe likes to say "Strong people are harder to kill than weak people and more useful in general."