Some basic anatomy questions (mainly tendons and teeth)

Hey got some basic anatomy questions. Any help would be greatly appreciated.
1) If muscles grow at a rate much faster than tendons, then wouldn't your tendons just rip out if you rapidly increased your muscle mass, or do tendons have a much higher tensile strength?
2) My dentist told me teeth stop growing cause they hit other teeth. So if you pulled out all the teeth in your mouth except 1 would you become like a bunny and have to keep cutting your tooth down?
3) Does cartilage hold bones together or just work as a shock absorber? I am guessing its the joining force from eating chicken wings lol but just want to make sure.
4) Roughly what percent of your body weight is tendons?
5) Can you work out tendons? It seems whenever people use them they get weaker and damaged.
6) Sorry to sound vain hahaha but isn't a 6 pack determined largely by the tension of the tendon? So in that sense wouldn't it be largely genetic, in the sense someone could have low body fat but not look "ripped"