I took my car to another shop and got the valve cover gasket, spark plug seals and cam end plug replaced for $70 cash. I didn't see them replace the parts, but I've dealt with the owner before and he's pretty honest. If not, then I'll put a big scratch on his RSX.
As for the tire leak. I haven't checked the pressure yet. I'll do that tomorrow and see if it's still leaking. A friend of my came over last week to adjust the valve stem. So, I hope that was the problem. If not, then I'm back to square one.