But the Ottoman empire would be between two and three times the population and with hugely more industrial and agricultural resources than Japan, so I'm not sure I understand the comparison.
Despite the apparent size on the map, the Fertile Crescent is neither large nor, as it happens, particularly fertile. Virtually all inhabitants live extremely close to the coast and rivers on a fraction of the land, necessitating an enormous navy just to remain whole on its own merits, rather than at the sufferance of the real powers. For all that the population could have been large combining all of those disparate bits, it's population still wouldn't hold a candle to that of the US or Russia unless both were truncated. And geography means that it will never achieve the kind of sustained economic explosion that made America and Russia (and is making China) into superpowers.
Regardless of political boundaries and infrastructure development, Tunis and Tripoli will economically be tied to Algeria and Italy more than the Balkans, Iraq, or even Egypt. So.... Great Power, yes. Superpower, no.
Also, why would oil wealth be worse than a wealth of any other industrial resource? The Ottomans had coal and numerous metals in the Balkans and Anatolia, so they certainly wouldn't be lacking in other important resources.
As for who they would sell oil to, any great powers who are neutral or allied with them, and quite possibly their rivals so long as war doesn't seem to be imminent, based on OTL oil sales.
Dutch disease. Natural resource wealth inflates currency to the point export industry becomes impossible.