As far as the PCV valve, you've probably got a restriction in the hose on the end of the valve. The valve is OK, but if the gasses can't escape out of the hose, they will build up and force the valve out of the grommet. To prove this, insert the PCV valve into the grommet with the hose disconnected from the PCV valve. It should stay in the grommet without being forced out.
If this holds true, trace the hose back...look for kinks, etc. If there's no external reason, there may be something inside it blocking flow. Also, if the hose is OK, trace it back further...somewhere there is a restriction.