Here you can find the track section from Vallelunga's official website. Only two tracks lenghts are listed, so it seems like I was right. I don't know about the chicane you are talking about, and it actually does seem weird to me. But the only different layout from the one I've raced into is the SBK one, which includes another corner, the one right after the soratte that brings back to the old track. They probably didn't get the homologation, that's the only good reason I can come up with...
Anyway, the national s2000 series, the GTs and all the bigger cars (F! included) use the long version, which is the new one.
As for Giovanardi in Pergusa, he was much faster than his colleagues, Larini included. Surely the Alfa played a big part, but there were 2 particular corners in which he was just fantastic to watch, the Proserpina and the 'Schumacher'.