So “Spider-Man 3” finally had its U.S. Premiere last night at the Tribeca Film Festival, and thankfully it didn’t rain on Sony’s parade. Variety has an amusing (well, maybe not to my friends at Sony) account of what it describes as the “barely controlled chaos” at a multiplex in my old neighborhood of Astoria, Queens, which the trade paper helps describes as “the East Coast equivalent of Van Nuys.” Our competitors have finally begun running their reviews — mostly mixed-to-positive, with lots of complaints about the 140-minute length — including the least enthusiastic (and shortest) three-and-a-half star review we’ve ever read in a newspaper. Just a reminder that The Post had the first print review in New York, and it ran a week ago.