There are lots of problems with speedsters in general:
In your scenario, if Superman used his super speed, he'd kill every single person he touched and - likely - was even next to considering the shockwave. All equipment like doors would be shredded as well. Plus you can't turn easily at high speeds so it's more or less a bullet.
The real problem with the scene as far as Superman in particular is this: Lex is in the Oval Office. There are literally windows behind him. Why not go through the windows instead of the entire building? Since this is Superman, he could have likely fried him from the air from a few miles away.