Re: Engine oil on the serpintine belt
Two possibilities came to mind...
Shaft seal on A/C compressor. Quite often, these will sling refr. oil onto undersides of hoods, but I think that happens when the A/C is engaged, so if its cold by you now, that may not be it. On the other hand, I have seen some leak even when A/C was off, they tended to run downwards and back then. Probably worth eyeballing, anyway.
Crankshaft seal on front of Timing Cover. A lot of times this area ain't the easiest to see into! But you might try using a shot or two of spray-on, hose-off engine cleaner, then watch it every few days. Seal can be replaced without yanking the cover.
I've really gotten into using engine cleaner on leaks the last few years. Saved on opening up stuff that was ok. Something about "Starting out with a clean slate", I think.