I have good news and I have bad news. First the good news - Christmas is coming. Now the bad news - It seems the only way to remove a broken bolt from an engine block is to drill it out - see you local mechanic for further details
Loose, broken, or worn valve train component. Remove the valve cover to find the problem.
On a 2.0L it is top leftside of the valve cover. It is a yellow handle that sometimes is broken off and it's just a little plug looking thing on the valve cover.
Could be a broken lifter or something along those lines. Will need to pull valve cover and visually inspect.
If you have done a compression check the next step is to take off valve cover and look.
use an extractor to back the bolt out of the hole then replace with new one
It can, which is not to say that it should.
Please restate the question. What are you talking about? Valve cover gaskets, valve cover, what? need a valve cover
Probably a bent valve cover from overtightening Replace or try to straighten then tighten to 10 inch lbs. only
Remove the broken bolt and replace it with a new one. There are several ways to remove that broken bolt. You can remove the valve cover and weld a nut to what is left of the bolt, wait for it to cool off then unthread the broken bolt. You can also drill out the center of the broken bolt and use an easy-out. You can also drill into the broken bolt with a left handed drill bit, sometimes the drill bit will catch and spin out the broken piece. I would go with the first suggestion.
I think there is no torque required for the valve cover as long as all are evenly tightened or the seal is flat on the cylinder head it will not cause any leak. If you have tightened the valve cover screws already and there are still leaks you might want to consider putting silicone on the valve cover gasket before you attach it or you might want to consider buying a new valve cover gasket.
There are valve cover bolts around the perimeter of the valve cover. You want these tight but not as tight as you can get them.
Remove the valve cover and look for a loose or broken part.