Most likely yes on both counts. With the saddle too high, the feet can no longer stabilize your body. They're too busy trying to reach the pedals, and you're probably rocking your hips, too. So you're perched on your perineum with your arms and shoulders working as outriggers. As for saddle setback, we had a big thread on that 10-14 years ago. You should look it up. The idea was that if your center of gravity is forward of your feet, you can't help but support the torso with your arms. If you sit bolt upright, that isn't much of a problem, but more you lower the torso towards horizontal, the farther forward your weight will shift. Moving the hips back shifts the center of gravity. That isn't as much as a problem for skinny pro climbers or sprinters putting out hundreds of watts on their downstrokes, but for the rest of us it's a consideration.