weightlifting might affect your height as it compress your spinal column. Go to http://www.giantscientific.com it has a lot of info on exercises and height increase tips
Majorly misinformed. Weightlifting incorrectly can give you bad posture, possibly leading to a slight hunchback but if you lift correctly there should be no problems for an adult or older teenager weightlifting. Unless you have an accident your spine should not be compressed at all.
(Website by Marc MacYoung, not me)