I had to give up heavy deadlifts and squatts about 5 years ago as my lower back just couldnt cope anymore.
I think deadlifts helps prevent back injuries. I swear by them. I don't go 'snap your sh
it up' heavy, but I go heavy enough to ensure that six-reps is my max/failure.
Squats I'm more careful with, because running is my 'main thing' and squats just kill my thighs and negatively impact running. So I go heavy, but low volume; just one set (after two warm up sets), but I am doing this three times a week. I'm not after being a body builder/power lifter, just strong for running.