for what it's worth, the picture is slightly tilted, so those guys aren't as bad as they look.
I was soloing (no pro) to the first anchor on sliding board two weeks ago and psyched myself out because the rock was slightly crumbly and I couldn't stop thinking about the mushed up crystals acting like ball bearings and me going for the 200 foot slide. sometimes it's all in your head, and once you lose that momentum it's really hard to recover. you gotta believe!
Dman's right though, weight over your feet is where it's at. but you have to be ready to change that mentality when the terrain changes. some of the friction climbing maxims like taking small steps, or sticking your butt out, are just plain wrong on many slab situations. sometimes you have to make a big rockover move on a high foot, and sometimes you gotta get your head right next to the rock in order to get the center of balance you need to move your foot up. trust your instincts if something isn't working, and don't be afraid to throw common knowledge out the window if it feels right for you.