Okay, gas in the oil most likely means that it is running rich. Most probably due to misfiring or just running like crap in general. Since you say it is struggling to run, I am leaning towards misfiring or jumped timing belt. Even when my computer died it would still run, it just wouldn't take gas or trip the fan relay. Misfire can be fixed by replacing the ECT, Oxygen sensors, spark plugs and wires. It might be all or just one of the above. Have you tried running the KOEO codes? If it's really running like crap and it trips the Check Engine light, it should have codes stored in memory. Here's the link for the self test procedure. You can most likely just bend a paper clip and stick it in both connectors.
http://www.shotimes.com/php-bin/modules.php?op=modload&name=News&file=article&sid=83
I would suggest running the KOEO (Key On Engine Off), KOER (Key On Engine Running), and SEFI (Cylinder Balance) tests. The KOEO will show codes in memory, the KOER will show errors found during the test, and the SEFI will tell us which cylinder, if any is causing the majority of your problems.
I'm not entirely sure about the condensation on the oil pan, but I don't think it points directly to anything. Mine always has oil on it (both my mains leak) and the road dirt makes a grease like putty.
I know that oil in your spark plug wells is not good, when I got my SHO, it had probably an inch and a half of oil in each one. But it still ran like a champ and would always accelerate and take whatever beating I was willing to subject it to. If you haven't already, change your oil. It'll only cost you about 10 bucks or so. If there's even a hint of coolant in the oil it'll definitely tell us if you have a bad head gasket, but if you don't smell coolant in your exhaust you're probably okay.
Follow the link and run the codes. It should shed some light on something. Most importantly, don't get discouraged. I've worried about mine for a year and a half, constantly nitpicking about things that aren't even important. Just keep at it and hopefully, we'll be able to solve your problems with minimal cost and trouble. If you get any codes, have any trouble, or think of anything else, post it. I usually check the forum 5 or 6 times a day. Good luck.