I always put some red RTV on that O-ring. No gasket, as it will space the O-ring too far away for a good seal. Been working on vehicles since I was 8, so when you get to tightening that pan gasket (cork) watch the edge of the gasket as you are snugging the bolts down and when the gasket JUST starts to bulge out a Little, THAT'S TIGHT, go no further and you will have no leaks. You're on the right track with being detailed.
Well...... I already did my oil pan. Hopefully it sealed right. I was going to use a gasket, and then I decided to try it without one, since the cork gaskets do have a tendency to squish out. I didn't RTV it and leave it overnight that was recommended. I used the rest of my expensive the Right Stuff, let it dry for about 1 hour. Layed the pan on the block. Let it sit for about 2 hours, then tighten the pan bolts just barely finger tight. Let it sit for another 2 hours, then torqued them down. I got a little squish coming out on a couple places. So.... I will know after I fire it up and check for leaks!!
There's so many ways to do stuff. I tend to be more anal and cautious just because I don't have that much experience.
I appreciate the input! I'm making notes from all the hot tips I get here!