I've read Ottomans can beat Italy easy if you can acquire coal. Capture their ironclads with your own and the med is safe, actually winning is a different matter I know nothing about.
If you can survive the initial Italian rush, that's the first step. With your Prize Ships, you should be able to build quite a fleet and take over the Mediterranean.
However, the big challenge is beating Egypt (can't DoW), Ethiopia, and the Boers.
My strategy for Egypt was to send all my trade routes to Morocco (NONE to Egypt, though I did get 4 trade routes from Egypt).
My enormous fleet gradually made their way down the west coast. I was about halfway through when there were 30 turns left, and started accepted peace with the Europeans, so that I could rush to the south. The plan was to take Cape Town and Port Elizabeth, and from there assault the Boers. In a peace deal, Elizabeth gave me a pair of cities right next to the Boers. The Boers easily had the highest score by quite a bit, but simply had 2 cities. For some reason, no one had attacked them. So I bribed Elizabeth/Victoria to attack and in a few mere turns, the Boers were no more.
Ethiopia was something I planned to handle on my own. I had a DoF with them, so while waiting for it to expire, I sent a dozen Rifled Cannons to get into position. When the DoF ended, I attacked, easily taking several cities. (Around this time, they also lost several to Germany, so perhaps my attack wasn't needed). I couldn't hold most of those cities, so as soon as I took them, I sold them to Egypt for massive amounts of gold. Was able to then eliminate Ethiopia.