The icons will disappear. Now that's for the PnR.
According to Po there, it looks like if you hold it, it will be pick and pop.
No idea how to slip a screen either.
You mean body up without fouling? Stay in front of the player when they start to drive, then immediately stop touching anything, especially jump or up on the stick.
At least, that's how I've done it. Doesn't really work all the time, but sometimes it does, especially with a bigger guy on a guard.