it does sound like he made it up. there's no scientific evidence, even if the statements are believable.
actually they all are ridiculous.
1) aerobic exercise cannot plateau because there is nothing gained from it, only calories burnt / fat loss. it is impossible for your body to not be burning calories from any exercise.
2) if aerobic exercise made you slower, then how do sports which require speed, football, rugby, american football, players maintain their speed.
3) age determines metabolism, not the other way round
4) this is from physical stress, if you are physically stressed you are pushing too hard.
5) exercise releases endorphins which makes you feel happy. if you are feeling stressed from exercise, you are pushing yourself too hard.
6) ...? random, wheres the proof