Red, most teenagers see the computer as a gaming device or as a communications medium. I know if I tried to get my kids to do any of the things you suggested they would baulk. Each of my kids has their own computer but none has shown any interest in using it constructively (in the narrow sense of the word), even though we have bought robotics kits with PC interfaces, design software, even games development software.
Interestingly, my son (almost 15) is still willing to come out fishing with me but views me as an obsessive (he's not stupid). He only wants to fish for a couple of hours at a time, whereas I hate going out for less than four.