It makes the voice in my head that tells me I’m lazy shut up

Timing. Not speed, or power. Speed and power can amplify the effectiveness of good timing and technique

Depends on the art. I got my TKD black belt after ≈3 years. It’ll probably be 12-15 for my BJJ black belt (I’m 10 years in and currently am a purple belt)

@Nic Rollins typically, a black belt in BJJ takes about 10 years. My promotion to purple was a bit delayed partly due to gym politics and partly due to the Covid lockdown and some other stuff. My main coach wanted to promote me in 2021, but it got vetoed with no real explanation

It was pretty good.

Strength and conditioning should be its own thing, separate from technique training and sparring. Calisthenics and body weight stuff can be done just about anywhere. I recommend that everyone should lift heavy stuff. Decent goals are 1/2/3/4 plates for overhead press, bench press, squat, and deadlift. Or .75x, 1x, 1.5x, and 2x bodyweight for those lifts, whichever is lighter as initial goals. They’re achievable for most individuals over time without steroids or anything too crazy. Understanding energy systems used in your goal (street fight/self defense, tournaments, etc) will dictate what you should optimize. Cardio is good for everyone for general health and wellbeing, but the average altercation tends to last less than a minute where anaerobic metabolism is the primary metabolic system used. This is where force output can be the highest.