I'm glad i have a little cautious kid - some of these stories are scary!
My DS4 was early in the 1st year milestones, except crawling and walking. He was average on those. I think he delayed crawling because he could get wherever he wanted really fast by rolling. He tried walking just before he turned one. He made it about 4 steps, fell, and didn't try again until he was 14 months. Then he walked with no falls like he'd been doing it forever. DS was always the cautious one - he didn't jump up with 2 feet until 3.5. He never really liked his tricycle, he won't try a bike, and he doesn't like his scooter (though a very stable one) because he couldn't figure it out right away. I think he just started doing the playground climbing walls at age 4. But he's an excellent mini golf player, and loves to run.