in 20 years and building 2,000+ bikes ive NEVER used a torque wrench on a bike
doesnt mean its right
xesh is right ( funnily enough because hes in the trade )
you need 2 . one for the high things like the bottom bracket ( ie a snap on or similar common jobbie ) and another bicycle specialist one for the small things like the canti mounts
i doubt i wont make any friends now but if someone is so arrogant not to admit that their " ive been doing it since time began ( not a personal dig stew , your post is just a representative of a certain viewpoint ) and my arm is 100% accurate " isnt perfect and once in a while needs checking against an accurate scale dont let them near your thousands of pounds worth of stuff
a pro will use correct torque . not every single time but they will make sure to keep a check on it .
the barnetts book gives general settings for common parts like stems , cranks , bars and whotnot
"It also has a seat. I don’t use it, but you probably will for the first few years until you build up the muscle."