EJ22E rebuild, and secret O-rings

[bosango]

Greetings all! I come here from a long history of driving VWs and, of course, rebuilding their engines. It's nice to see that there's a good support community among the Suby crowd. Maybe it's a mid-life crisis, but I'm selling my last VW and just picked up a very nice '93 Legacy with a well-running leakless engine and a knock on the #3 cylinder. I'm planning on taking it to bits soon and replacing, at the very least, the crank and rod bearings, and rings, as long as I'm there. Of course, I'll check all the clearances and wear limits and all that nonsense to make sure everything is reasonably reusable. This being my first Suby rebuild, I have some questions:

1) On the diagrams in the factory manual, there appear to be a few O-rings between the block halves. Are these available separately and, if so, from where?

2) I've read all the warnings about replacing the rear seal. Does this still hold true if the case is opened? I mean, it's going to fall out anyway so why not replace it?

3) Is it really necessary to replace the head gaskets? I know the purists will say this must be done, but it sort of goes against my VW ways where it's almost a badge of honor to reuse parts until they completely fall apart (a little copper spray = good as new?). The rocker and head assemblies seem to be in fine shape so I was just planning on leaving them be.

4) I'll follow the proper procedure to remove the pistons, but I'm wondering why the halves can't be pulled apart with the pistons still connected. Is there just too much friction there, or too much of a risk of gouging the case?

5) Why did I wait so long to get a Subaru?