I think Voyager's EMH certainly demonstrated that holograms have the capacity for solution, but I also consider him a unique case - he evolved to use that capacity because of the circumstances which Voyager encountered. If the ship had never been towed into the DQ, it's unlikely the EMH would have had the same opportunity.
I view a being like Data in a different light, because they're really no different from organics - the capacity to grow is always there, and is the main impetus for development. Data's evolution into sentience wasn't like the Doc's, where he could just add the desired data to his programming.
Yes, I agree. He would not have had the chance at all. It was Kes who had sort have taught him to feel emotion and have fun, and he had worked that into hobbies such as singing and all. If not for the DQ, he wouldn't have had the chance.
Although, in Voyager, there were other Isomorphs (Holograms) that were featured. They all showed character as well. One group was a ship full of Isomorphs looking to rescue others of their kind. They all seemed to show that they had very human traits. Also there was the episode where a war broke out on the holodeck between created characters andother Isomorphs who found their way to the holodeck. They also portrayed human characteristics. And lastly, there was the murderous Isomorph who killed all of his crew and almost killed B'Elanna.
So overall, I would say that Hologams are humans, but made of different material.