Compression issue/oil in the upper intake manifold

Okay, so far the plugs are new. The coil has been replace less then six months ago. Gives you an idea how long I have been dealing with this issue. Wires have been replaced when I changed plugs. Replaced the PVC valve two weeks ago. I am getting oil in my upper intake manifold. A bit of a knock tends to go away or lessen when it warms up or reaches higher speeds. Very rough reverse. When I try to reverse there is no idle speed I have to give it gas or it will not move. Replaced my camshaft sensor last week when I could not idle over 2,000 rpm's. If I rest my computer the car seems fine for a day or until it gets a moment to idle for to long. I get error code p0304 cylinder four misfire. And sometimes I get error code p0300. More then one misfire. Cylinder two is my guess as to which other one misses. Looks like it has a bit of build up in the plug well. Not to terrible but an issue yet. Uh what else, lol. Oh yeah, there is no fuel dampener on the fuel line leading to the rail. Spark plugs seem to be dry fouled. But no oil as far as I can tell in the wells so far. Although it seems to be going through oil and fuel faster then it did when I bought it two or three years ago. Oh, changed the intake manifold gaskets. Due to a vacuum leak. Air filter is new as well. I tried to replace my fuel filter/regulator but AutoZone got me the wrong one. It looked similar, but when I put it in, car would not turn over until I put the old one back in. Seems to not be a fuel pressure issue though. So I hope you can help me. And I hope this information can narrow it down for you. It is the only car I have at the moment. So I may still end up making things worse day by day.