You can- depending on the car but I wouldn't because you would ruin the engine. Most cars today have a rev limiter-where it will stop at a certain RPM.

Depends on the motor. No everyday car that I know of can get to RPMs that high without throwing a rod, trashing bearings or something else catastrophic happening. A Kawasaki Ninja 400 superbike on the other hand can easily hit that RPM. A quick article I just read said that is actually the peak torque RPM for its engine. 

Generally, small displacement engines with many cylinders can spin faster without destroying themselves than large displacement engines with fewer cylinders can. A hypothetical 3.0L V12 could spin much faster than a 3.0 V6 because the mass of the individual moving parts in the tiny V12 is significantly less than in the average sized V6. Formula 1 engines are of this nature, though they are not V12s. They can withstand RPMs over 12,000 at times. 

Sure, right before your engine explodes.