Bouldering is a ton of fun. It also usually costs more strenght than toprope or lead climbing. If you go to a climbing gym you'll usually kill your arms with a couple bouldering routes first and then go for some toprope/lead routes.
Funnily enough stopping is easy, you just have to drop. That's usually something that your skiing teacher will tell you over and over. But like a deer in the middle of the road seeing the incoming headlights people just tend to freeze in panic when they loose control.