1. Where are the Sable Company headquarters? It is stated that Midland is "the home district of both the Korvosan Guard and Sable Company", but we also have The Great Tower and Endrin Military Academy. I´m confused.
2. Where are Ornelos Manor? It is mentioned, but I don´t get where it is located in the city. Is it by The Acadamae?
The Great Tower is the headquarters of the Sable Company. I haven't found anything in Midland that fits the bill.
Most noble manors have not been pinpointed, to give DMs the chance to put them somewhere themselves. I would definitely place Ornelos manor close to the Acadamae. Looking at the map of Korvosa, I would go for the largest building on Ornelos Street, to the west of the Acadamae grounds.