Industrialization is absolutely dependent on coal, and coal is not easy to transport. That's why the industrial giants will primarily be those which actually have coal, like Britain and Germany, even though other countries may get some of their excess coal.
Italy will never be able to become an industrial power on the scale of Germany, Britain or even France - the industrial capacity it got OTL was because the southernmost limit of waterways in the 19th century was in northern Italy (so you won't get coal imports to North Africa, or even south Italy), and it attracted capital because of its cheap labour. If the tragedy/farce of Italy's performance in WWII teaches something, it is that coal builds empires rather than the other way around.
France has potential, especially if the excess population at the start of the 19th century wasn't gotten rid of through war, but rather through settling in resource-rich areas to the east, allowing it to become core French areas.
Spain won't become an industrial giant, but it has plenty of room for expansion nevertheless. While the terrain of Spain might be a bit of a problem, the biggest obstacle (in other words, the thing that has to change) is its economic situation from the 16th century forward.
The Ottoman Empire is perhaps the power that could grow the most compared to actual growth, and holding territories in the Balkans will be the most important part of that process. Please refer to
this excellent post for some ideas on how it might come about.
Polish-Lithuanian Commonwealth also has tremendous room for expansion, but it was handicapped by policies which turned it from one of the most progressive and rich empires in Europe to a decaying cesspool, laughing stock of the continent - its in a similar seat to Spain.
I hope that might give some ideas.