Orochimaru has summoned the previous 4 hokages....can he solo the entire leaf village?
Yes he can if he very smart about it. He almost destroy the Leaf the first time he try and he only had fodder ninjas with him. He has the fourth with him who can end the fight before it being just by throwing Kunai's before you can blink. We already saw what Madara could do with only a portion of Harishrama cells. That just leaves the Tobirama and Hiruzen. We don't know what they can fully do. We only have ad idea. Until we can see what they are able to do then this is left in the air.
Yeah. It took the third sacrificing his life to stop him last time. This time the Third and Fourth are on his side. Orochimaru stomps it. I mean, Pain solo'd the village, pretty much, before barely losing a close fight to a prepped Naruto while he was at less than 100%.