OT(as far as the OP is concerned) questions from someone who is considering taking up climbing.
1. Isn't what you are doing in the video called bouldering?
2. Do you usually climb in your jeans? I am wondering does it allow you required flexibility?
3. Do you work on your core for climbing or climbing works your core?
4. What would you say about artificial walls and bouldering arenas for a beginner?
1. Yes that is bouldering, but bouldering is a subset of rock climbing, as is sport climbing.
2. Bouldering is frequently about balance and power, for some problems flexibility isn't as crucial. I climb in jeans outdoors, sometimes it's the best option as rock can quickly cut through lighter materials. My jeans are skinny and stretchy.
3. Climbing works your core, simply by climbing more and more.
4. Don't play the grades game, don't buy a hangboard. Go into a gym and have fun on the boulder. Don't try too hard and hurt your tendons, they take years to grow accustom to the stress induced by hard bouldering.
1. Yes. Bouldering is one type of rock climbing.
2. Very occasionally. It does limit flexibility somewhat, but I wouldn't skip climbing because I forgot my shorts.
3. Both.
4. They're great. Just make sure to get outside eventually!
(edit: formatting)